Friday Reads – July 21, 2017

If you have something you feel we should read or include in a future list, please email us at [email protected].

116 comments

  1. Can I add another “City Metric” post to this?
    It affects longer-distance travel for Londoners, at the least.
    Link here, – about bi-modes & false expectations & pronouncements is the politest way I can put it.

  2. Not sure why but I found this week’s Friday Reads under Industry News on the home page whilst the main page feed has Friday Reads for July 14th up.

  3. The article on jaywalking is interesting and echoes a recent piece from the University of Illinois Law Review (https://works.bepress.com/lewyn/125/) which also shows how the parent of a child killed by a hit-and-run driver was accused of homicide for letting the child cross the road mid-block. The comparative safety statistics for pedestrians in the US and UK, fail to take into account that walking is twice as popular in the UK, thus the safety rate here is 4 times better than in the US even though we allow jay walking.

  4. “Jaywalking” is an American-English word, but one that is well understood (though rarely uttered) in the UK. While it is not, of itself, an offence, crossing the road recklessly at an inappropriate place (or against a red light) can certainly be prosecuted – at least in theory.

  5. On the topic of speed limits, nobody ever goes at 20mph. If you try to, then buses will start overtaking you (where possible, anyway) and then pull over in front of you at the next stop.

    On city centre parking, I would never drive into central London during the day, but I have often found it useful to drive into or through, and park, in central London between say 10pm and 7am. (Currently live near to PoP.) Would be a shame if this stopped being possible. Furthermore, try going at 20mph at 3am, you will get night buses and huge lorries doing dangerous things to overtake!

    The problem with London traffic is not the number of vehicles but the fact that you often get 3 or 4 roads merging into 1 due to the road layout, which also means inefficient traffic lights because you can’t program a “green wave”, and large goods vehicles blocking roads at peak hours.

  6. Re the 20 speed limit. Didn’t tfl announce that they were going to fit limiters to buses to prevent them exceeding the speed limit – and have they quietly dropped the idea…?

    I found it interesting that there is a central source for sat nav providers. I don’t own a car – but do rent them occasionally. Many cars (even quite ordinary ones) come with built-in sat nav these days. Most show the prevailing speed limit. Except…., I’ve never driven any car (even brand new – “17” plate – models) where the sat nav device ever showed a 20mph limit, they always show 30mph.

  7. @ Island Dweller – the bus speed limiter programme has not been abandoned. It is delayed until 2018. I assume because there are enormous practical issues with fitting yet another piece of technology to vehicles. It is worth noting that several bus operators have fitted driving driver guidance equipment to their buses to monitor individual drivers and to ensure slower, calmer and more economic driving behaviour. Unfortunately some of those systems then result in the buses not working properly because they don’t reach high enough temperatures to burn off certain emissions through filters. Also some buses become “bunged up” thus worsening their performance and an increase in breakdowns. I’ve lost count of how issues like this I’ve read about recently. I suspect TfL and their suppliers are having genuine difficulties in creating a technology that does not wreck the vehicles it is fitted to. Given TfL don’t own the vehicles then all that will happen is that the operators will demand indemnities or extra money for “performance risk” if the technology affects vehicle reliability. Furthermore slowing down buses just puts operating costs up and revenue down. If I want to travel at the speed of a snail I’ll ride on a snail. I won’t ride on a bus travelling at snail like speeds.

    The Assembly Transport Cttee in their recently released Bus Safety report were critical of the delay to the limiter scheme and demanded that it be accelerated (irony alert!). TfL have a few weeks to respond to the report recommendations but I expect they will “kow tow” given no one is putting forward the case for effective bus services any more. The more we slow down and “hobble” bus services the less well used they become and we will end up back in the dysfunctional mess of a network we had in the 1980s if we are not careful. TfL are currently unravelling almost all of the bus enhancements made in the Livingstone era 2002-2008. As I completely disagree with just about everything the Cttee put in that report I shall stop now before I put myself in hospital due to extreme anger over their ridiculous findings. 😉

  8. @ John 26 July 2017 at 07:52

    On the topic of speed limits, nobody ever goes at 20mph. If you try to, then buses will start overtaking you (where possible, anyway) and then pull over in front of you at the next stop. . . .
    Furthermore, try going at 20mph at 3am, you will get night buses and huge lorries doing dangerous things to overtake! . . .

    Although I am not happy with the 20mph limit (another topic for another day), I am not certain that there are very many ‘bus routes / main roads where it applies (excepting some short stretches) which are likely to be used by HGVs and are wide enough for ‘buses and HGVs to overtake.

  9. I love the article on the computer failure in Melbourne…. I have travelled on the trains in Melbourne and the loop is a wonderful idea, in principle….

  10. How often in the proposed 20mph areas do buses exceed 20mph now? When I worked for LT (over 50 years ago I have to admit) we were only interested in acceleration performance up to 20mph as it was considered that buses rarely travelled at more than this speed. I suspect that not many reach speeds much higher except where the road conditions permit, rarely in the area shown on the map. Stop frequency has a speed limiting effect. I do not see that modern buses have a much better performance in speed/acceleration terms than the Routmaster.

  11. Jim. The buses I use routinely reach 30, even though the limit is 20. You can feel the drivers slowing down again for the speed cameras. Some of the new hybrid buses can accelerate relatively smartly for something so big.

  12. @Island Dweller – showing my age – but the acceleration of electric vehicles doesn’t surprise those of us who remember the F1s on the 607, which could out-accelerate any contemporary petrol vehicle. This shouldn’t be news – electric motors generate maximum torque on starting unlike chemically fuelled traction.

  13. @WW
    Diesel particulate filters (which get bunged up when their engines are driven slowly) are a particularly poorly thought out technology. Why fit something that requires travel at 50-60 mph to ‘clean’ itself to a vehicle that will spend most of its time limited to 20-30-40mph. It’s not the additional technology that’s the problem, it’s the existing tech on the engine.
    “I won’t ride on a bus travelling at snail like speeds” – Do I take this to mean you want to ride on a bus being driven with reckless disregard for such tawdry things as speed limits?

  14. Anonymike:

    I too am mystified by this widespread belief that lengthy runs at 55mph+ are necessary for diesel filters to ‘clean themselves’.

    I can quite believe that periods of running with particular power demands and/or particular engine speeds could be needed (though, as you say, such a requirement does seem to be an ill-thought-out piece of design). But how the particulate filter is supposed to respond to a particular road speed just baffles me (do they have GPS-based road-speed measuring equipment incorporated, or are they somehow informed of the effective transmission ratio by fancy sensors in the transmission?). Is J. Bonington Jagworth alive and well and working in the particulate filter design labs?

  15. Lengthy runs at high speeds means the engines working around its peak output, so exhaust gasses are at their hottest. Hot exhaust gasses are necessary for the emissions systems to work properly. Accelerating from standstill to low speeds may not take long enough for the gasses to get hot.

    Future engines will likely have some mechanism to get hot air into the emissions bits

  16. Re Malcolm, Anon, Anonymike, WW & Island Dweller,

    With modern engines (both petrol and diesel) over the last 25 years of development the relative heat (energy) content of the exhaust stream has been decreasing over time as:

    1. More energy is usefully converted to mechanical energy e.g. increased energy/fuel efficiency used
    2. More waste heat is removed via the cooling system as this is more thermodynamically efficient than before*
    3. More gear ratios available in the gearbox have reduced average engine revs.
    4. Turbos create more low end torque and hence have reduced average engine revs.

    And at the same time more devices have been added to the exhaust system which all scavenge heat from the exhaust stream as their energy source which come in 2 main categories:
    5. Turbo chargers – which have also become more efficient (effective at heat removal) over the time period
    6. Additional emission control devices. e.g. catalytic converters, selective catalytic reduction, exhaust gas recirculation**, diesel particle filters

    Which all means there can be very little heat/ energy left to power the emission control devices as they are further away from the engine as the proceeding devices have already removed what heat they needed or could hence there is frequently very little left at the tail end of the exhaust system where the Diesel Particle Filter is.

    * note extra cooling grills (often “creatively”) added to bus engine compartments where there have been engine upgrades over time as more heat ends up in the engine bay

    ** EGR is selectively disabled according to engine running parameters e.g. temperature (engine and external), revs, fuel injection rate, exhaust chemistry, gear selected, engine running time (+ at least another 5) so they only really work in freeflowing dual carriageway and motorway driving after 20 minutes running, which is one reason we have NOx issues in towns and cities as EGR just isn’t running on most vehicles. Though in the case of a German and a French car manufacturer the only time the EGR was running was during emission tests which was apparently a bit to selective in terms of running conditions for some regulators as the EGR was never used on most vehicles.

  17. In the latest issue of modern rail Christian Wolamr fires back in a right to reply to an article in the presvious months issue, where he was called Lord HAw Haw for his anti HS2 stance and some of the arguments used by him against it. It’s worth a read for the chuckles alone.

  18. @Rational Plan – whilst I don’t agree with everything that Wolmar says,the attack on him merely serves to emphasise the impression that HS2 is a cult not an intellectually robust project.

  19. I would like to remind the Commentariat that matters and discussions concerning the validity of the High Speed 2 scheme are not for this House.

  20. @ Anonymike – who said anything about breaking speed limits or that such limits were “tawdry”? I certainly didn’t. There is a combination of factors that have been brought together that are crippling London’s bus service. As soon as journey times become too long and / or services unreliable people vote with their feet – sometimes literally. What on earth is the point of sitting on a bus, as I did recently, to make a journey that 2 years would have taken 18 minutes but took 45 minutes? I am not terribly fit but I could have walked the distance involved in way less than 45 minutes. I was not in a great hurry but other people on the bus were and got off 3 or 4 stops before their preferred stop because they were going to be late.

    I thought the point of a bus service was to get people where they want to go in a reasonable journey time. When buses are slower than walking something is *very* seriously wrong. No one in their right mind would use such a service if they want an effective journey. For those who cannot walk far or who are otherwise encumbered and do not have access to minicabs / uber / a car then we must ask the question as to why they should be inconvenienced by a hopelessly slow service? The short answer is that they should not be but no one in any position of power is fighting for the bus service. Instead it is under attack from those advocating walking and cycling. For those of us who actually *prefer* to use public transport this is an unedifying spectacle.

  21. WW: Your vigorous defence of the bus service is admirable. However, Anonymike pulled you up because your message could have been read as condoning buses breaking the 20 mph speed limit, with your reference to snail-like speeds.

    If this limit (in many London boroughs) is a major factor in the deplorable overall slowing of bus journeys, then adjusting the limit might be an appropriate approach, but we’d probably all agree that leaving the limit in place but tolerating bus drivers exceeding it would be unwise and unhelpful.

    But actually I think the 20mph limit is a very minor issue, and there are other reasons for bus journeys taking longer today than a few years ago (road changes, increased congestion and so on), most of which are, at least in theory, amenable to measures within the ambit of TfL.

    The 20mph limit is there for good reasons. I do not know whether it has been unequivocably shown to save lives, but that is certainly the intention.

  22. Knowing as I do,a little about the performance characteristics of conventional (ie non-hybrid) combustion engines,I’d have to be shown some pretty compelling evidence to be persuaded that a 20mph limit (in which cars often do not get into top gear) is less polluting than a 30mph limit (in which they do)…I understand that other factors than emissions are taken into consideration…

  23. I haven’t had a car that gets into top gear at 30mph for years. My last diesel – 2004 wasn’t comfortable in 4th at 30mph. 6th wasn’t viable below 50mph. My current automatic petrol car has an engine that will run at 1250 or so revs/minute on low throttle so does run in 4th gear. Whether at 20mph or 30mph, steady speed and low throttle settings will deliver good economy and therefore low CO2. Constant accelerating and braking to negotiate “speed bumps” in the road is much, much worse.

  24. 100andthirty: Quite. I think slugabed may have meant 4th gear when he referred to “top gear”, but even so, I would suspect that the difference in consumption between a steady 20mph and a steady 30mph is close to negligible (one way or the other) in any modern car, but speed bumps (at least in the absence of regenerative braking) are the real CO2 villain. All we need to get rid of these is a big reform in attitude so that all drivers obey the limit (whatever it is) at all times without being bumped into doing so. We may have some time to wait for this, however…

    More widespread 20mph limits might, however, have a beneficial effect on emissions if they nudge a useful number of car users onto trains, pedal bikes or feet.

  25. It must also be the case that if buses are going ‘at snail’s pace’ because of congestion then Uber/taxis/minicabs/cars will be little quicker (though considerably more expensive). At the point that it becomes quicker to walk than to use a bus the only viable alternative is some form of rail service (or, in some limited circumstances, water) or bicycle. Any road based transport will offer little benefit.

  26. @quinlet, WW

    Is there any call or appetite for expanding bus lanes? Surely, just as cycle highways and superhighways have been created, additional and linked up bus lanes should be in planning to ensure that people can still get around and the Capital can still function.

  27. There are plans for more bus lanes, but all the easy ones have been done. There’s clearly no point in putting in a bus lane if the level of bus service is low, and not much point if there is no history of congestion at that location. Elsewhere there does need to be a road with space for two traffic lanes, at least in the direction of the bus lane. These days the bus lane probably needs to be wider to allow for overtaking cycles. You have also to take into account the needs of frontagers, whether they be residents with no off-street parking or businesses needing deliveries, let alone customers. This all leads to some difficult decisions that need to be taken with one group (buses, general traffic or frontages) inevitably going to lose something.

  28. IIRC, Liverpool scrapped most of its ‘bus lanes but the jury seems to be still out on the result.
    Coventry did likewise earlier this year for a six-month trial, but have been unable to find any report on the outcome.

  29. It may well be difficult to find reports on the effect of bus lane removal.

    But such reports, if they existed, would probably draw the “obvious” conclusion that such removal disadvantages bus riders but benefits people riding in cars and vans. A “jury” would, as ever, find it difficult to rule on whether or not one of these outweighs the other.

  30. Re Malcolm, Slugabed, 130,

    Emissions.

    1. There is some confusion over which emissions are the main worry, what causes them and what can be done to reduce them.
    From regulatory point of view there are 4 categories:
    A) CO2
    B) CO, Hydorcarbons
    C) NOx
    D) PMs

    The traditional focus (1970 to 2000) was on A) & B) with a focus on C) & D) starting in 2000 but the main focus still being on A) which also drove a previous governments dash for diesel.

    The court judgement focused on the health effects of C & D which are disproportionately from diesel and in the case of C if you live near an airport JET A1 as well .

    2. MPG is the wrong metric for fuel efficiency if worrying about CO2 as there is an in build bias to diesel (circa 4.7%) so miles per MJ would be better (as would taxing Petrol and Diesel per MJ not per L, a duct tape solution is the *rumoured* increase in year 1 diesel VED that is being proposed for the next budget).

    3. NOx is largely a function of:
    X) high compression ratio and temperature (a big issue for diesel as this is big part of the reason for Diesel higher efficiently hence a trade off to reduce NOx)
    Y) acceleration
    Z) rpm

    NOx reduction technologies are performing much worse than expected in on road conditions than test conditions.

    4. As a different example to the 20/30mph case my fairly modern manual euro 5 petrol car will run (provided you don’t want to accelerate) in 4th gear at 20mph and 6th at 30mph with a 45% improvement in measured mpg at 30.

    5. DfT have known for years that speed bumps and not green lighting increase emissions but doing something about it would reduced fuel duty & VAT take hence HMT we never going to agree until the court result. Ditto reopening closed off rat runs but DfT haven’t mentioned that yet…

  31. Malcolm: “crossing the road recklessly at an inappropriate place (or against a red light) can certainly be prosecuted – at least in theory” – and in practice.

    Some years’ back I was attending a course with part given by West Midlands Police, and they recounted how a bus driver swerved to avoid a pedestrian, the upshot of which was someone fell down the stairs and was badly injured. The person who fell sued the bus company, who then traced the pedestrian .They were successfully prosecuted for stepping out into the road about six metres from a light-controlled pedestrian crossing and causing the accident.

  32. Thank you Ngh…that was a clear overview.
    My interest was raised when,a short while ago figures released which suggested that air pollution was responsible for 9,000 “additional” deaths in London alone the previous year.
    Road deaths that year stood at approx.1,700 for the WHOLE of the UK.
    At this time in my local area there was a vociferous debate about introducing the 20mph limit and installing speed-humps to ensure its compliance.
    I pointed out the foolishness of cutting road-deaths by,say,10% by using techniques which might increase emissions by 10%…

  33. @Malcolm
    A properly designed bus lane does not produce delays for general traffic. This is because the capacity pinch points on any road are at the stop lines of traffic lights. It really doesn’t matter how many lanes of traffic are available on the link as the capacity at the junction is limited by the number of lanes and, at best, the half of the time when the lights are green. A well designed bus lane stops just sufficiently far back from the stop line so that the reservoir of traffic can just clear in one green phase. This means that the bus is guaranteed to get through on the first phase but that there is no capacity taken away from general traffic. Magic, eh?

    You will be lucky to find any study of the removal of bus lanes from Liverpool as this was an act of faith not the result of an objectively reasoned approach. Once you believe the outcome there is no need to study it.

  34. Quinlet: When a bus lane allows buses to overtake other traffic, that other traffic is delayed. Your argument only tells us that adding a bus lane (when done right) does not cut down total traffic capacity. But no-one said it did.

    Ask if letting someone push into the supermarket queue in front of you delays you. Of course it does.

    Mind you, the individual cars (as there are a lot of them) are each only delayed by a small amount, whereas the bus is advanced by a larger figure. So subscribers to the “immaterial” theory (which says that delays below a certain threshold, such as five minutes, do not count as delays at all) could share your belief that bus lanes “magically” benefit some without disbenefitting anyone. Personally, I do not buy this one either.

    I still support bus lanes, but on the grounds that benefitting bus riders over car riders will alter the total proportions of the two, to the ultimate benefit of all, as buses make better use of the limited road space. But this is a different argument altogether.

  35. @ Malcolm – I am well aware what was being suggested about speed limits. However I did NOT say what was being suggested. I try hard to be clear and really dislike people trying to put words in my mouth. I do have an issue with the current “fad” for 20 mph limits in many boroughs. I understand the road safety and accident risk concerns. We seem to have got to a very unfortunate position whereby politicians and certain lobbyists no longer believe buses are a safe mode of transport. Their actions and demands are dressed up as “safety” but there is a complete lack of “big picture” thinking. Every time you slow buses down, make vehicles more expensive and denigrate the role of the bus driver you make it harder to staff and operate the bus network efficiently. The harder it gets the worse the service is and people are then forced to switch to vastly more dangerous forms of transport to get around. What on earth is the point of that?

    @ LBM – TfL have acknowledged that they need to do something to try to speed up buses through more “bus priority”. However much of what they have said is related to junction design, small amounts of extra bus lanes and timing / special priority at traffic light controlled junctions. TfL have not published any lists of what work they have delivered but they do state a quantum of schemes “delivered” in their quarterly reports. Without the detail it’s impossible to know what’s been done and if it is having any effect. As Quinlet says the “easy stuff” has been done long ago.

    We do need to understand that it was the previous Mayor who abolished the long established traffic hierarchy in London and who thought “smoothing traffic” worked. It doesn’t. It just worsens things for the more efficient modes like buses. We should also note that the Bus Priority Unit at TfL was abolished to save money under the last Mayor. Finally we should also note that the mad dash to remove gyratories and add segregated cycle lanes has had a negative impact on buses. Some people will no doubt rejoice about that having seen buses as a long “protected” part of LT and then TfL. The fact that it has worsened both the practical and cost efficiency of the bus network and costs hundreds of millions of pounds in running extra buses to maintain the same frequency, reduced patronage and revenue and is now resulting in an ongoing programme of cuts to services seems not to be an issue for anyone. What an utter mess.

  36. @Malcolm
    Think about it this way:
    You have a road with 30 buses an hour along it. At a specific set of traffic lights, the lights are green for 45 seconds and red for 75 seconds (I’ve used these just to make the numbers easy) so that a cycle lasts 2 minutes and (assuming the bus flow is even) one bus crosses the stop line every green phase, with or without a bus lane. Therefore, during each red phase one bus is in the reservoir leading up to the stop line. Adding the bus lane does not give you any extra buses in the reservoir leading up to the stop line – there are still only 30 buses an hour. Indeed, the bus lane would have helped keep the flow even. What has changed is that the bus in the reservoir is now a later bus than would otherwise have been the case. The total traffic flow at the start of the bus lane remains the same, the total traffic flow across the stop line remains the same, including the number of buses. There is no additional delay to any other traffic caused by the bus lane.

  37. quinlet: Supermarket queue. I will make no other reply, as we do not need a pantomime “yes it is”/”no it isn’t”.

  38. Alison 30 July: I am fairly sure that at one time (if not now) passengers were not allowed to travel on the stairs when a bus was moving. If so, and assuming there were notices to that effect, it looks as though it was the passenger’s own fault. Possibly this rule became unenforceable with the demise of conductors.

  39. I have never been completely convinced that reducing a speed limit from 30mph to 20mph reduces pollution. If we assume a car travelling 60 miles at a steady 30mph then the engine is running for 2 hours. Is this really worse than a car travelling at 20mph with the engine running for 3 hours? To put it another way, is an engine running at 30mph more than 50% more polluting than one running at 20mph?

  40. Littlejohn: Probably not. But it is much more complex than that. As has already been mentioned, there are various kinds of pollution, and some measures (such as the former trend to diesel cars) can worsen one while alleviating another. The speed limit change could have all sorts of indirect effects (through discouraging car use, for instance). The speed at which vehicles are most efficient and/or least polluting will depend on the design of the vehicle. And so on. Many other factors come in to play beyond a simple estimate of the polluting effect of one vehicle travelling at one particular speed.

    There is some evidence, also, that people’s desired vehicle use is better modeled by constant time than constant distance. That is, if it takes longer to get places, we will tend, on average, to spend the same amount of time travelling (a shorter total distance) in a month, say, rather than choosing to spend more time travelling the same distance.

  41. @Malcolm – the important point to remember is that pollution is a product of the amount of fuel burnt, and as you say, the amount of fuel needed to move any particular vehicle at any particular speed will vary; the relationship between the two is definitely not linear. In particular, the energy consumption will be influenced by whether starting from rest, braking, coasting and so forth.

  42. Re Graham H

    the important point to remember is that pollution is a product of the amount of fuel burnt,

    Only for CO2 (my category A above) all the other emissions have far greater dependencies on other things rather than just fuel burnt as the primary metric.
    For example Diesel will tend to give you circa 10x more NOx than Petrol (per litre/ MJ /kg), due to the higher compression ratio and combustion temperature this is a big part of the reason for Diesel’s higher fuel efficiently hence a nasty trade off to reduce NOx.

  43. Littlejohn,

    I have never been completely convinced that reducing a speed limit from 30mph to 20mph reduces pollution.

    Stating the obvious, you are assuming that the car only has an internal combustion engine. So your logic is relying on the fact that an internal combustion engine is more efficient at 30mph than 20mph. To some extent this is true because it is geared to run most efficiently at its most used speed.

    If the car is pure electric (as the future will be) then fairly obviously it runs more efficiently at slower speeds. For a start there is less wind resistance. More importantly, you want to avoid static friction by avoiding coming to a complete halt (keep those wheels rolling). Slower speeds tend to reduce stop-start behaviour in heavy traffic (go with the flow).

    The biggest issue I have with the “30mph is more efficient than 20mph” argument is that any truth in that statement relies on the manufacturer optimising efficiency for 30mph. Given the incentive to optimise efficiency for 20mph or a 20-30mph band they would do so. But, in my opinion, water under the bridge. As soon was we move towards electric the logic that means that slower speeds are more energy efficient will be hard to argue against.

  44. @NGH -I understand your point about the difference between diesel and petrol but surely if you burn more diesel you get more NOx than if you don’t, comparing like with like (which was what I was trying to say)?

    I may have noted before that when I had the fuel efficiency brief at DTp,my colleagues and ministers really couldn’t understand why diesel was unacceptable (for the reasons stated) and pushed very hard for bizarre or trivial fuel economy measures such as making sure you emptied your car boot of wellingtons before travelling, just to show that they were doing something, anything really. (I even inherited the production of a leaflet to this effect – widely interpreted amongst the HEOs as requiring people to go to the loo before setting off -rumours of a TRRL research project to this effect had extensive currency). But then this was the ’70s…

  45. @PoP – ‘So your logic is relying on the fact that an internal combustion engine is more efficient at 30mph than 20mph’.
    No, I didn’t say that at all (or at least I don’t think I did). What I was saying was that (in very simple terms, disregarding speeding up, slowing down etc) for 20mph to be better overall it would have to be at least 50% less polluting than 30mph since for any distance it is running for half as long again. Please also note the question marks. I was asking if 20mph is in fact that much less polluting, not putting forward an argument in favour of 30mph.
    Regarding an all-electric UK, that I fear is a long way off. The current (ouch! -sorry) plan is for all new cars to be electric from 2040. Even if that timetable is adhered to it could well be 40 or more years before we see the end of fossil fueled cars.

  46. Littlejohn,

    I think Graham H had already given you the answer. You need a certain amount of energy to get from A to B which is basic physics. You generally don’t save energy by getting there faster though there may be a very minor effect of the time taken if you have your headlights on and perhaps a more serious effect if you have the air-conditioning going full blast.

    It is well established that going at a maximum of 50mph instead of 70mph saves a lot of fuel. It is also easy to verify if you make the same long motorway journey a couple of times. In times of fuel shortage the government reduces speed limits on motorways to save fuel. If it is true for for going from 70mph to 50mph even though it takes longer at 50mph why should it not be true going from 30mph to 20mph (other than possibly that the engine/gearbox combination isn’t very efficient at 20mph)?

    The point about how long before electric cars come into common use is very relevant. If we had 20mph limits other than on main roads (as is increasingly happening in London) then the attractiveness of petrol and diesel engines goes down and that of electric cars goes up. You need to plan not for how the world is today but how it will be in the future and you need to take into account how your decisions affect the future.

    Which do you find less exhausting? Walking for 10 miles or running for 10 miles?

  47. If this discussion is becoming concerned with physical accidents now versus ill health over time then we must (?) take into account the total years of life lost from either cause and cost to society.
    Physical accidents happen to all ages.
    Illness from pollution is likely to have a long slow build, most likely coming to a head in later life.
    The discussion is almost pointless without some proper figures.

  48. @PoP: A general rule on fuel consumption is that this increases by roughly the square of the velocity.

    With regards to the 20 mph limits, I thought that these were introduced on the grounds of road safety? So that Smomby’s^ had a better chance of surviving when they stepped out into road without looking…

    ^ – Smart Phone Zombies…

  49. @PoP It’s even more complicated as people switch to electric and hybrid. These vehicles can recoup most (not all) the energy lost in slowing down, so the penalty of frequent acceleration/deceleration which affects ICE (internal combustion engine) vehicles is much less of a penalty for hybrid/electric.

  50. @quinlet comment “plans for more bus lanes, but all the easy ones have been done”
    I wouldn’t agree with that. I could suggest many roads (roads where buses are stuck in congestion) which would benefit hugely from adding a bus lane. To give just one example, Eastcheap in the City, heading east towards Tower. The reduction of Byward street to one lane eastbound (to create the cycle superhighway – which I approve of) has had the unfortunate side effect of causing persistent tailbacks on Eastcheap, usually jammed all the way back to Monument. That has made service 15 unusable for me – it is now so desperately slow. There is ample room for a bus lane eastbound along Eastcheap – all it needs is the political will to remove the parking meters….. Political will that seems to be missing….

  51. SH(LR) – yes, in any collision the lower the speed the less serious the likely consequences.
    PoP – ‘If it is true for for (sic) going from 70mph to 50mph even though it takes longer at 50mph why should it not be true going from 30mph to 20mph?’. Last comment on this but I didn’t say it wasn’t, I just asked if 20mph was more than 50% less polluting than 30mph. Nothing directly to do with fuel consumption but with the length of time an engine is running.

  52. Littlejohn,

    I am assuming pollution in an internal combustion engine is related to the amount of fuel used rather than the length of time the engine is running.

  53. Re PoP, Littlejohn and Graham H,

    I disagree with several (many) of the recent comments but Littlejohn’s understanding is pointing in the right direction. Engine and transmission efficiency at low speeds is bad and this has been mostly missed in comments.

    For Euro 5/6 cars (either fuels as both engine types will tend to be turbo or twin charged these days) the theoretical optimum fuel efficiency speed is achieved when running in :
    a) top gear
    b) engine rpm = idle rpm + circa 700rpm (may be slightly higher for some engines but not lower)
    The result will be over 40mph for almost all cars.

    Real world testing by Emission Analytics (who integrate testing equipment into portable setups used for moving emission tests) suggests that the optimum fuel efficiency speeds (both petrol and diesel) for the top 10 best selling UK cars (Focus, Fiesta, Astra, Corsa, Golf, Polo…) are in the range 42-50mph with most centred in a narrow range around 45-46mph. [Emission Analytics also advise TfL on emissions.] EA also apparently did some work at the time of the introduction of the first 20mph zones that suggested they would increase NOx emissions with real world driving and have also cast some interesting light on the Highways Englands smart motorway speed management strategies (and not in good way for HE).

    Optimum efficiency speed (based on Wh/km or equivalent) of electric vehicles is estimated to be at 15-20mph.

    EA have also done some work on the effect of weight saving on mpg which suggests Graham’s highlighted 1970’s going to the toilet to save weight would only improve mpg by 0.0055mpg in a modern car.

  54. re Littlejohn @ 13:30

    “Regarding an all-electric UK, that I fear is a long way off. The current (ouch! -sorry) plan is for all new cars to be electric from 2040. Even if that timetable is adhered to it could well be 40 or more years before we see the end of fossil fueled cars.”
    But that isn’t what the detail of government announcement said, the reality is certain Hybrids could still be sold after that date.

  55. Re Graham H

    I understand your point about the difference between diesel and petrol but surely if you burn more diesel you get more NOx than if you don’t, comparing like with like (which was what I was trying to say)?

    Most often how you burn the fuel (either) has a much bigger effect on NOx emissions than how much fuel you burn for example an engine in the 15-20mins after a cold start will emit more NOx than driving in the fast lane of motorway in 3rd gear with the accelerator fully down. Hence why NOx is much harder for people to get their heads around including DfT as fuel use is not the main correlating factor indeed you often get more NOx with higher efficiency combustion, very different to CO2!

  56. Perhaps we could all agree that keeping traffic moving at a reasonably constant speed is a good thing both for fuel economy and emissions. The challenge is achieving that objective with congestion, traffic calming and so on!

  57. @Island Dweller
    “all it needs is the political will to remove the parking meters”
    Quite. And the political will to deal with the howls from businesses on Eastcheap who can no longer get deliveries to their doors and who are concerned that their customers will go elsewhere. When I said that all the easy bus lanes had been done I was thinking about politically easy, not just physically possible.

  58. Deliveries? Delivery vehicles don’t rely on meter bays. In any case, a delivery truck would block the lane, but only for a few minutes. Using that space for parking meters blocks a lane all day. The City Corporation has been surprisingly progressive in reducing car usage (the legacy of Peter Rees perhaps), so I’m sure they could be persuaded to remove these meters if onky tfl would request it.

  59. @ngh – so,to be clear, you can burn a litre of the same fuel in different ways such that the NOx is different? (In the ’70s in DTP,since NOx wasn’t regarded as an issue, I wasn’t told this by the boffinns at TRRL/BL).

  60. Deliveries and parking at meters are two different things, yes, but both fairly incompatible with a bus lane. A part-time bus lane, with deliveries only permitted outside its hours of operation, might do the trick, but it would be a compromise, and I don’t know how well it would work in the particular road cited. But the general conclusion stands, I reckon, that fitting in lots more bus lanes throughout London would not be particularly easy, politically speaking.

  61. Graham: This is likely to be the case. ngh will know more details, but the contrast with CO2 is evident. Just about all the carbon in the fuel ends up as CO2 in the exhaust. Whereas the oxides of nitrogen resulting from burning fuel mostly derive from atmospheric nitrogen (though there is a component from nitrogen in the fuel, but generally a minor one). Most of the nitrogen molecules taken into the air intake of an IC engine pass harmlessly through it without reacting at all, but a fraction are converted into oxides. Exactly what fraction varies enormously with the combustion conditions and with the fiddly detail of what happens further downstream in the exhaust system.

  62. Re Graham H,

    Exactly.
    NOx (mainly N2O, NO, NO2) in internal combustion engines is mainly formed from the reaction of atmospheric Nitrogen and Oxygen. In diesel engines the combustion is always lean overall (i.e. fuel : oxygen ratio is less that stoichiometric) which means there is still a reasonable amount of oxygen not consumed in combustion. At the high pressures in the cylinder around maximum compression and the high temperature at the flame propagation front (1350C+) it allows the usual inert (at room temperature and pressure) nitrogen to react with oxygen in equilibrium reactions:

    N2 + O NO + N
    N + O2 NO + O

    With high temperatures and pressures pushing the equilibrium to the right at the flame propagation front (but at room temperature and pressure the equilibrium is effectively completely to the left), plenty of similarity to Haber – Bosch Ammonia production process.

    The other thing to bear in mind is that most the things you do to reduce NOx in the engine (ignoring exhaust system clean up) will increase PM formation and vice-versa.

  63. The equilibrium arrows in the comment above got wiped by the site autoformatting…

    Picking up on Malcolm point NOx is indeed generated in very small quantities overall in the range of 0.01% – 0.3% of the exhaust gas content pre exhaust treatment compared with typically 71% Nitrogen content in petrol exhaust and 67% in diesel exhaust so Nitrogen conversion to NOx of between 1 in 250 to 1 in 10,000.

    NOx has lots of interesting chemistry including ground level ozone formation.

  64. Another important contrast is that CO2 is entirely a global pollutant. My CO2 will be a problem (or not) for the whole world (via climate change etc), and the victims will typically be far remote (in space, and often in time as well) from the source.

    Whereas NOx will doubtless have some global effects, but the effects of most immediate concern (in Oxford Street etc) are the local effects, due to locally raised concentrations of the gases – the same applies, of course, to particulates.

  65. Which is more damaging NOX or particulate matter? Am I correct in thinking that the least polluting diesel cars have a lower compression ratio? How does this affect the different pollutants? What is the best engine to have for a mixture of journeys? I suspect that the answer to the last question is a diesel Plug in hybrid to get your local journeys on electric angry long distance on diesel. Or a Tesla.

  66. Re Purley Dweller,

    Which is more damaging NOX or particulate matter? Am I correct in thinking that the least polluting diesel cars have a lower compression ratio? How does this affect the different pollutants?

    Both NOx and PM are damaging.
    Lower compression ratio should have lower NOx* but will have higher PMs from some sources (e.g. Poly Aromatic Hydrocarbons PAHs ) as they will combust less at lower CR.
    * but there are plenty of other factors too e.g. injector design

    What is the best engine to have for a mixture of journeys? I suspect that the answer to the last question is a diesel Plug in hybrid to get your local journeys on electric angry long distance on diesel. Or a Tesla.

    Anything but Diesel so Petrol/CNG/LNG preferably the later as there isn’t a NOx vs PM trade off in engine design. (See LNG trucks and buses with the equivalent of Euro 0 exhaust systems and the lowest emissions.

    On small /medium cars there isn’t enough space for the batteries, diesel engine and the emission control equipment hence you’ll only get SUVs or large saloon car Diesel Hybrids (inc PHEV), so the smaller more efficient car route will be Petrol PHEVs.

  67. I know that I said my post yesterday (14.32) was my last comment but can I join in the current discussion? These two items off the web are interesting although they both come with a Health Warning – one is promoted by a ‘make everything 20’ organisation and the other by a motoring organisation so possibly neither is entirely impartial.

    http://www.20splenty.org/emission_reductions.
    http://www.theaa.com/public_affairs/news/20mph-roads-emissions.html.

    I was unable to find stats for Euro VI but that may not matter as most cars on the road at the moment are probably not Euro VI compliant anyway. I take it that ‘Drive Cycle speed limit’ means the complete journey, which answers my query about the extra running time inherent in lower speeds. What the ‘Pro 20’ paper shows is that reducing the speed limit reduces overall emissions for diesel cars but not for petrol; arguably increasing them (how do you offset increased NOx and CO2 with reduced PM10?). The AA paper also claims that reducing the speed limit from 30 to 20 increases petrol consumption by more than 10% (and so increases CO2 emissions) contrary to perceived wisdom – maybe because the car is running in a lower gear? Can this really be true? If so then PoP’s fallback position that ‘possibly the engine/gearbox combination isn’t very efficient at 20mph’ could well be correct and a wholesale change to a 20mph speed limit may not be a Good Thing.

    Of course, none of this alters the fact that a 20mph speed limit may in any case be justified on road safety grounds.

  68. I believe tyres and brake pads are also a source of vehicle particulates so the type of engine won’t do anything about this (unless inductive braking can replace brake pads!)

  69. Re Littlejohn,

    The AA paper also claims that reducing the speed limit from 30 to 20 increases petrol consumption by more than 10% (and so increases CO2 emissions) contrary to perceived wisdom – maybe because the car is running in a lower gear? Can this really be true?

    Yes see my comment on 1 August 2017 at 19:55

    …for Euro 5/6 cars (either fuels as both engine types will tend to be turbo or twin charged these days) the theoretical optimum fuel efficiency speed is achieved when running in :
    a) top gear
    b) engine rpm = idle rpm + circa 700rpm (may be slightly higher for some engines but not lower)
    The result will be over 40mph for almost all cars.
    ….
    Real world testing by Emission Analytics (who integrate testing equipment into portable setups used for moving emission tests) suggests that the optimum fuel efficiency speeds (both petrol and diesel) for the top 10 best selling UK cars (Focus, Fiesta, Astra, Corsa, Golf, Polo…) are in the range 42-50mph with most centred in a narrow range around 45-46mph. …

    Hence 20 is even further the wrong side of 42-50 than 30 is so no surprise the fuel efficiency and CO2 is worse.

    The AA work is based on real world tests at Millbrook proving ground (probably with testing equipment supplied by Emission Analytics.) including showing that adding speed bumps to 30mph road actually increase fuel consumption by 47% and point out that DfT (in it previous incarnation at the time) knew that reducing speed limits from 30 to 20 would increase emissions in 2000 (17 years ago).

    The 20’splenty work is based a modelling exercise done by Imperial 4 years ago where they looked at revised drive cycles based on driving several routes in London then extrapolating predicted emissions based on another model of official NEDC emission tests data* (As the VW scandal showed these were very wide of non-gamed test results and ever further removed form emissions in real world conditions (tests done by EA)) with lots of questionable assumptions and dubious ways to present the results.
    *There is an acronym in the modelling and IT worlds GIGO – Garbage In Garbage Out and unfortunately the data source they used has since been discredited.

    The annual excess death rate from emissions in London is circa 5 times the number of road deaths in the UK annually, hence 20’splenty will find it much harder to campaign in future and have so far avoided mentioning the any comparison with the excess death rate from emissions.

    Also note that yesterday East Cheshire Council had to call in the police to investigate “deliberate and systematic manipulation” of air quality data reporting to DEFRA thus allowing more developments to go ahead council wide as emission problems were understated. It isn’t just the car manufacturers at it!

  70. ngh,

    I for one accept that it is quite possible that 20mph is more polluting than 30mph. But I reiterate the point that this is only because car manufacturers have effectively made this so by gearing the car to have a “sweet spot” at around 30mph. So, if they re-geared cars inappropriately, it would be quite possible that 30mph was more polluting than 40mph. Should we then change the speed limit to 40mph?

    I am just saying this is entirely the wrong way round. Society should be deciding speed limits and manufacturers of petrol and diesel vehicles (whilst they continue to exist) should be designing their cars to run best and least polluting at those speeds.

    By the way, I think it is well established that the choice of 30mph as a limit was decided entirely arbitrarily with no scientific basis whatsoever.

  71. Re PoP,

    But you are ignoring the fact that major underlying issue in all of this is thermodynamics and that ultimately decides what gearing is possible and efficient (a look at the torque and power curves of current engines is very instructive).
    Ultimately society can’t decide the laws of physics! If society decides it doesn’t like them and ignores them then there are consequences and the moment to face up to the consequences in the UK has started to arrive.
    In CO2 terms 30 is already more polluting in CO2 terms than 40, it isn’t just possible but the current reality for small/medium cars.

    Most of the current ways to get better low end Torque to reduce CO2 emissions at lower speeds in real driving conditions by allowing higher gearing ratios at those speeds will increase emissions in some other category (i.e. increasing compression ratio, supercharging, remapping ECU chip are all bad for NOx if going for low end Torque). The fundamental issue is that Turbochargers won’t do anything much useful for optimising emissions reduction at 20mph. The sweetspot in term of useful extra torque will be boost of circa 2bar to the compression ratio from the turbo which won’t happen when trying to drive economically at 20mph.
    In terms of new technology which might help, electric valve actuation (for Diesel, Petrol, CNG, LNG) will help but will also help efficiency at the 40+mph sweet spot too and for spark ignition engines (Petrol and some CNG/LNG) replacing the spark with multipoint multitime infrared laser ignition which will again improve efficiency at whole range of speeds but not change the current efficiency sweetspots speeds being well above 30mph.

  72. ngh: Fascinating stuff. But I still cannot grasp why it is not possible to optimise an engine and gearbox for 20mph. How does the engine, operating at its best non-polluting rpm (and providing x kW of power) know whether it is propelling a particular car at 30 mph, or a somewhat heavier car (with greater rolling resistance) at 20 mph through a 50% lower gear ratio?

  73. Re Malcolm,

    In brief for the moment.
    At the optimum efficient RPM the engine will be producing ~80% of the maximum torque but <30% of the maximum (horse)power (at 40+mph so assume 100% different ratio rather than 50%) so the engine at 20 mph through a 100% lower gear ratio doesn't have the power required unless the fuel injection rate is increased which destroys what the aim of the change is! While the engine might have the torque for a 100% lower gear ratio there isn't the power delivered to the wheels with a 100% lower gear ratio to avoid the car slowing down rather than running at constant speed… Hence the engine sees what is connected to (same reason the engine (and driver) can "feel" that it is going up hill, as the power requirement has increased)

    You probably can design an engine and gearbox for a 20mph optimum but the car would be less driveable above 30 in real traffic and get overtaken on Motorways by heavily laden Mark 1 Landrovers towing a trailer or 800t mobile cranes… (or it might perform OK but resemble a bubble car in terms of functionality). Neither is going to sell.

    If you try to solve the gearbox issue by swapping to electric transmission by going down the extreme PHEV route you would get fairly close but still run into other issues.

    The platinum bullet solution to the court case (focused on NOx and PMs) is to ban diesel ASAP which will solve the problem overnight (see Putney High Street monitoring station data from Ride London closure days) but as that isn't going to happen the government has chosen the complex mess solution over decades instead (average car lifespan at 15+ years).

  74. ngh, Malcolm

    I have to admit I am dubious about this. I could accept this for an engine of given size but don’t know enough physics to understand what the consequences would be if you made the engine smaller.

    In any case, I think this is an argument that will be increasingly irrelevant in future. If you have a decent hybrid then ideally you run the engine at two speeds – optimal and off. The optimal speed would then be a very slow one to minimise air resistance and reduce the need to charge the battery

  75. It may be worthwhile pointing out what the NICE (National Institute for Health and Care Excellence) guidance said about speed bumps, as, unsurprisingly, what was reported in the press did not quite reflect what was written in the NICE report.

    “Some evidence on physical speed reduction measures like humps and bumps suggested that individual measures may increase motor vehicle emissions by encouraging decelerations and accelerations. But evidence from area-wide schemes does not back this up.

    So where physical measures are needed to reduce road injuries, the committee agreed that area-wide schemes should be designed to minimise the impact on air pollution. Because the evidence was uncertain, the committee recommended this as an action to consider. ”

    https://www.nice.org.uk/guidance/ng70/chapter/the-committees-discussion#clean-air-zones-2

    On the point about speed bumps, air quality and safety, in general, I believe speed bumps have been installed on residential streets with generally lower traffic volumes so even with speed bumps, air quality won’t be the same issue it is on high volume arterial roads or places like Oxford Street.

    If there is a residential street with high traffic volumes and speed bumps, that suggests a bigger issue with traffic in an area.

  76. Reynolds953: Good points there. But it raises the question of what is an area? To what extent (if any) is the dangerous atmosphere on the Oxford Street pavements (for instance) affected by any speed bumps on nearby smaller roads? Or is the effect so local (see my earlier comment) that extra NOx and particulate pollution caused (perhaps) by speed bumps can be totally disregarded because the speed bumps are not in pollution hotspots and the pollutants dissipate (or dilute themselves) before they can get to any such hotspots?

    I know it is not strictly evidence, because the pollution we are talking about is often described as “invisible”, but the frequent city-wide haze over the whole of Beijing suggests to me that “local effects” can spread over kilometres, rather than the tens of metres which would be necessary to apply my tentative argument in the previous paragraph.

  77. @NGH: What about CVT (Continuous Variable Transmission) gearboxes? Would they not offer a solution in this case?

  78. There are quite a few roads in suburbs that are residential but have quite high traffic volumes and speed bumps. Eg close to where I live, Hale End Road – significant traffic artery between eastern Chingford and Walthamstow, including the 275 bus route. Enough traffic for lengthy jams to develop on rainy school mornings and when the Highams Park level crossing is closed. Recently speed-bumped as part of the “Mini Holland” scheme (after earlier chicanes still failed to prevent people speeding).

  79. @ Philip – we are cursed with wretched speed bumps in Waltham Forest. They are everywhere – on main roads with high volumes of cars, buses and vans. I can just about accept them in residential side roads where a small minority of drivers drive like lunatics. However they do nothing at all for the comfort and safety of bus travel – try using the stairs on a double decker as it traverses a hump. Ridiculously dangerous and a hazard I have to deal with whenever I use my local bus. They are also not exactly compatible with newer designs of low floor buses which have limited clearances on some hump designs. Another local route I use has to deal with loads of such humps and the drivers spend half their time veering all over the road to avoid the bus being bashed to bits as it encounters the humps. If you ever wanted to make bus travel uncomfortable and borderline dangerous then the road hump is the thing to deploy. Yet another policy where all the consequences and risks were not properly considered.

  80. Re SHLR,

    But CVT still tends to have a higher gear ratio at higher speeds, the only real solution is to go all electric transmission Boris bus style.

    FT Alphaville Column (registration but not subscription required) has good take a part of EV economics published this afternoon:
    https://ftalphaville.ft.com/2017/08/03/2192188/electric-vehicle-realities/

    Re WW,

    ” If you ever wanted to make bus travel uncomfortable and borderline dangerous then the road hump is the thing to deploy. ”

    I’d transfer all roads with Bus routes to TfL control from councils to stop such silliness.

  81. @NGH
    But traffic speed, especially in residential roads, is a killer and speed humps are demonstrably good at reducing accidents by reducing speeds. What’s your alternative?

  82. Quinlet
    USUALLY ( Note the qualifier ) residential roads are not bus-routes.
    Also “cushion” as opposed to full-width humps are possible – buses can usually negotiate the former.

  83. quinlet asks for alternative ways of slowing traffic in residential roads. I have two offerings – one is an extended campaign to treat speeding like drink-driving now is, with severe punishments and substantial peer pressure. However, this may not work, so my next suggestion is to harness the power of technology, and build cars with inbuilt GPS and updatable maps, which know what the speed limit is at any given point, and do not permit it to be exceeded. (This would also enable finer-grained control of speed, enforced slowing near junctions, and possibly other benefits that I haven’t even thought of).

  84. quinlet: although traffic speed is a killer, so is pollution. There has been some suggestion here that in targetting speed we are “spending a guinea to save a pound” (in fatality terms). This claim does at least sound plausible, though it also provokes the usual “more research is required”.

  85. If tfl adopted the French clean air stickers system, for London, called Crit’Air vignettes, pollution levels could be reduced to legal limits within months.

    All cars would need to display a sticker that displays its emission level (there are 5 or so levels with the most polluting vehicles in the highest level). As pollution levels rise one or more of the highest emitting levels of vehicles are banned to keep pollution within legal limits.

    Those with highly polluting vehicles can keep them but with some days when they will not be able to use them or if they need to use them every day there would be a big incentive to buy a lower polluting vehicle.

    This could initially be rolled out to the congestion zone. Rather than making (mainly rich) polluters pay it would just ban them.

  86. Buses operating in parts of Glasgow covered by a Statutory Quality Partnership display stickers indicating their emission levels – mainly Euro standard, but also with LC for Low Carbon and EV for Electric Vehicle.
    So far as I am aware, there is no scheme in place for any other type of vehicle.

  87. Re Quinlet,

    “What’s your alternative?”

    Looking at the bigger picture , starting with London roads:

    Most accidents especially those that result in death or serious injury in London occur at road junctions (this hasn’t really changed over the last 15 years of detailed stats) with at least 70% at junctions with over 60% of the total at giveway or uncontrolled T junctions (inc offset Ts) or crossroads (the other 10+% at junctions being at traffic lights, roundabouts, sliproads and driveways etc.).
    Wet Weather and Darkness also significantly increase accident casualties rates.

    So surely the focus on accident reduction should focus on those junctions as they are the biggest factor? Unfortunately making junctions safer (and more efficient) is expensive and take time which is why the quick and “cheap”* 20mph zone philosophy was followed. Reducing parking, other visual obstructions and detritus near junctions to improve sight lines, improving street lighting lighting, anti-skid surfaces would all make a significant difference but would take time and cost lots. Lighting is being improved significantly in some area with new LED lighting. More traffic lights (inc pedestrian crossings) and roundabouts…

    (*ROSPA)

    The excess death rate from the high pollution levels is 4+ times the KSI rate on the roads (or 65+ times the road death rate) in London so when you combine looking at pollution and road deaths, speeding is a very very small factor when trying to reduce the total.

  88. <very dangerous misuse of statistics alert>

    People who are killed on the roads generally had many years of life ahead of them and probably had a good quality of life at the time of death. Furthermore, there are substantial adverse knock-on effects to the economy and to the relatives of the person killed.

    People who have their lives shortened as a result of air pollution are, in the main, older and less likely to have a good quality of life. The amount that their life is shortened by can probably be measured in weeks on average and normally not more than a few months at most.

    A simple comparison is very misleading.

    </very dangerous misuse of statistics alert>

  89. Littlejohn: I should have clarified that the person who fell down the stairs had just stood up and was waiting to exit the bus which was approaching it’s stop (adjacent to New Street station, in fact)

  90. Re PoP,

    “”

    Indeed but the point was to illustrate that there might/will be a change in priorities from the current focus on speed and the local authorities have effectively been put on notice to this end, it will also have chilling effect on commercial development in certain areas.

  91. NGH & PoP
    The excess death rate from the high pollution levels is 4+ times the KSI rate on the roads (or 65+ times the road death rate) in London
    Really?
    We have already discussed this , erm, extremely dubious & “wobbly” so-called statistic before, haven’t we?
    Sorry, but this cannot be allowed to become “gospel”, because it isn’t.

    [<Snip for incomprehensibleness> PoP]

  92. Considering “people KSI (killed or seriously injured) in road accidents” versus “excess deaths from road-induced pollution”.

    Whatever the actual numbers, there is another important perceived difference. The people accidented have names, histories, relations, grieving friends etc etc. The “excess deaths” have none of those features, because we cannot tell who they are. Epidemiologically we know there must be such people, because for certain immediate causes of death (lung cancer, for instance) there are significant differences in the rates as between more and less polluted areas. But any given individual who died of lung cancer in a polluted area might perhaps have died anyway even if it wasn’t polluted.

    It is only natural and human to react more strongly to the death of an identified individual than to an abstract difference between two numbers.

  93. PoP: As you probably know, it is possible to ‘adjust’ the statistics for the kind of issue which you mention (instead of counting individuals killed, you count total years of expected life sacrificed – and you can even weight these years by presumed quality). It would be good to suppose that “scientific government” would use such things to determine where best to spend “life-saving” money. Good, but perhaps a little optimistic.

  94. @NGH, Malcolm
    The various suggestions you have made for reducing speed are all good in principle – and I would add fitting smart speed governors to cars which will automatically limit the speed of the car to the prevailing speed limit. These currently exist in a few vehicles. However the time needed before any of these suggestions would actually have an impact (including the time to get a political decision in favour) is very significant and, in some cases, so is the cost. We are where we are, and the proposal that we should actually make road safety worse in the short run, in the expectation that other policies might possibly improve matters in the longer term, is really not viable. Speed cushions, as a practical alternative, along with speed tables at junctions and horizontal deflections, such as chicanes have been preferred over speed humps for many years now, because of bus and ambulance objections. They will still slow down buses and, indeed all traffic.

    The root of the problem is the unwillingness of the police to enforce speed limits (and most other traffic regulations) over generations, which has led to the widespread abuse that occurs. It’s hard to see any other area of activity where it would be accepted that average behaviour should be illegal but given that the average speed of traffic on motorways is now about 76mph, that tells its own story.

    @Greg
    There are actually an awful lot of residential roads that carry bus routes. They may not be the trunk bus routes but as they are where people live they are an obvious place for buses to go. Even some main roads are predominantly residential. Examples of the former include Nightingale Lane in Clapham and Amherst Road in Hackney. Examples of the latter include Clapham Common North Side and Essex Road in Islington.

  95. PoP
    I was referring to the entirely fake so-called “safe alchohol limits”, which have no scientific basis at all ….

  96. quinlet: I agree with a lot of what you say here.

    There will never be a consensus about the “root of the problem”, but I would observe that the general attitude that “speeding offences are not really offences” cannot be entirely blamed on police non-enforcement of them. By diverting their limited resources towards other things (e.g. inter-personal violence) the police are following public attitudes, rather than causing them. It is probably impossible to untangle cause and effect in this matter, and it’s not strictly a transport issue anyway.

  97. qunilet,

    The root of the problem is the unwillingness of the police to enforce speed limits (and most other traffic regulations) over generations, which has led to the widespread abuse that occurs.

    Er? Could this just possibly be because, in many cases, it is not their job to do so?

    Whilst the police have the power to investigate and prosecute any crime, there are also many other agencies (and theoretically even private citizens) who have the power to bring prosecutions.

    The police will, of course, concentrate on offences that they are primarily responsible for but they do this with regard to the resources they have and the seriousness of the crime. So, for example, driving without a seatbelt on is regarded as a less serious offence as allowing three children at the back of a car not to be wearing seatbelts. In the former case there is no individual innocent victim and so the offence is unlikely to be prioritised – but it could be used as an excuse to stop the car if other offences were suspected.

    In the case of many traffic offences such as contravention of street signs including bus lanes and box junctions, the police are not the primary agency responsible for enforcement. Typically they may be the Highways Agency, TfL or the local borough. If there is a persistent problem brought to the attention of the police (such as parking) they would rather work with the appropriate agency in order to provide a long term solution instead of a fairly pointless blitz on offenders.

    It is rare that a major traffic operation is carried out solely by the Metropolitan Police. It will probably also involve the local council and possibly even VOSA or the Border Agency So it might not be a failure on the part of the police to provide the necessary resources to implement one of these.

    We have a problem in our borough with parking by a London Borough of Croydon primary school situated right on the border with Surrey and in fact most of the school is located in Surrey. The Metropolitan Police are aware of the problem but resources are limited and in any case, although they have the necessary power, they are reluctant to enforce parking regulations in Surrey. If, for example, the case was contested it would mean a trip to a magistrates court in Surrey rather than one nearby in Croydon.

    The borough of Croydon want to enforce the regulations but as the offences take place in Surrey they have no powers to do so. Surrey could not care less as they would rather spend their times sorting out their own school.s. So as your see, generalised statements such as the one you made, are superficial and don’t get to the heart of the problem.

  98. @PoP
    The Police have been the primary agency responsible for enforcing all traffic laws until relatively recently. Parking in London became the responsibility of the boroughs (and TfL) in the 1990s and other local authorities in the country have adopted that responsibility more recently. Since the early years of the century, the boroughs and TfL in London have become responsible for enforcing minor moving traffic regulations, such as box junction, one-way-streets and bus lanes, but, outside London, local authorities have taken on only bus lanes in a few cases. All other traffic law, including speed limits, drink and drive, mobile phone use when driving and dangerous driving remain the responsibility of the police as the primary agency. Indeed, only the police have the power to stop vehicles for enforcement purposes – essential where liability rests with the driver, as opposed to the keeper.

    So, even in today’s terms the police’ lack of interest in enforcing speed limits continues to take its toll. However, this is not new and the lack of police interest in enforcing any traffic regulations goes back at least 50 years, setting up a climate in which traffic laws become, in effect, advisory and motorists have responded accordingly.

    I take Malcolm’s point that more resources for traffic law enforcement would mean a reduction in resources for other more important law enforcement – this is the argument the police put forward. But it seems to me to be utterly pointless to make a law or regulation if you then have no great intention to enforce it. It just brings the law into disrepute. A consequence of the decriminalisation of parking and minor moving traffic law enforcement has been that the regulations more closely suit what is wanted and what the local authorities are prepared to enforce.

  99. It is not the case that speed limits are not enforced. They often are – plenty of people have points on their licence for speeding. And some of these are for speeding within built-up areas.

    I entirely accept that speed limits are not enforced as well as they might be, and the evidence, as you say, goes zooming past anyone driving on any motorway.

  100. quinlet,

    You have a rather strange view of how police prioritise and how the process works – or ever worked.

    For a start, although operational decisions are their own, policing policy is the responsibility of the Mayor. The police are no more free to set their own agenda than the Commissioner for Transport is. Prior to this, guidance came from the Home Office as to how a police force was to operate.

    The above produces some potentially awkward issues as a constable is sworn in to keep the Queen’s Peace etc. as if he/she were master(/mistress?) of his/her own actions and he/she is totally accountable individually for those actions even in situations where officers are effectively acting en masse under direction of a supervisor or even pursing guidance from above.

    So the police are not free to pursue their own policy as regards traffic or anything else and never have been. There are also various issues under the Human Rights Act when it comes to traffic offences – especially reasonableness and proportionality.

    Much more relevant, dealing with traffic (and behaviour on buses and taxi touting) is primarily dealt with by a section of the Metropolitan Police called Safer Transport. To identify them the relevant officers have ST shoulder numbers.

    As the Mayor controls the budget for Safer Transport (separately from the rest of the Metropolitan Police) he effectively determines the number of officers available. He also sets their priorities and targets they should meet. Not surprisingly, the Mayor and the officers who have to deal with what happens on the streets might have differing views to you as to whether to concentrate on issues such as taxi touting (which often leads to other more serious crimes which in turn produce traumatised victims) rather than run-of-the-mill traffic offences.

    Another priority that Safer Transport has concerns dealing with traffic violations and other incidents that directly lead to peak period traffic congestion because of the economic consequences to London. Because of the direction stipulated, keeping traffic moving and how to achieve that is a higher priority than booking a person. If the objective is to keep traffic flowing, you do not achieve this by getting bogged down booking an individual who was foolish rather than malicious.

    A further priority relates to reducing deaths on the road. Sometimes the best way to do this may be enforcement by means of a summons or fixed penalty notice but often other ways are more appropriate (e.g. awareness training for cyclists and lorry drivers).

    Like the Commission for Transport, the Commissioner for Police is responsible to the Mayor. Technically police officers are employed by the Mayor’s Office for Policing and Crime (MOPAC). If you disagree with policing priorities you should complain to your Assembly Member or to the Mayor’s Office. Don’t blame the police.

  101. I have not said that there is no enforcement of speed limits at all, but that it is inadequate to ensure that speed limits are adhered to, even approximately. A situation where average behaviour is against the law, as with motorway driving, just brings the law into disrepute. Spasmodic attempts to enforce leave motorists quite unsure as to what is acceptable and what is not and hence the outcry from some motorists when speed cameras were introduced. ‘Unfair’ was the cry to the point when Ministers insisted that all speed cameras were painted hi-vis yellow so that motorists knew they were there. Imagine if shops had to paint all their CCTV designed to stop shop-lifting yellow.

    PoP
    I am quite aware of the formal accounting lines as they are now and, indeed, as they were prior to 2000. However, the actuality left the police with considerably more freedom than these accounting lines would suggest. For example, the Metropolitan Police Commissioner of the day was quite open in saying that the Police would put no resources into enforcing the GLC’s footway parking ban when that was introduced in 1975. And all the way through the 1980s, the Police made the same statement about any attempt to introduce new controlled parking zones. This led almost directly to the decriminalisation of parking enforcement, with the boroughs saying that if the police wouldn’t enforce then they would.

    I quite agree that the particular style of enforcement can vary and that not everything deserves to be penalised by a fine or similar. However, the proof of effectiveness of any enforcement style is in the outcomes – is the law respected or not? Quite clearly, for most traffic law, the law is not respected, which certainly suggests that the style of enforcement is not effective. Contrast this with bus lane enforcement in London where high levels of detection through CCTV have led to dramatic reductions in infringements (and dramatic reductions in the numbers of PCNs issued).

    At the end of the day, I still maintain, that it is pointless to maintain a law and then not enforce it or ensure that it is complied with. If there are insufficient resources then perhaps the law needs to be reconsidered. If the Police are unwilling to enforce but other agencies are then perhaps a transfer of responsibilities is justified.

  102. So who is responsible for enforcement measures like box junction cameras and average speed cameras? Is it the highway authority for the road?

    Of course, measures like these just bring howls of protests from motorists who complain “it’s just raising revenue”.

    If it was just about raising revenue then I’d have thought the highway authorities could do a MUCH better job of bringing in more money given the number of roads with no enforcement and the general disregard of speed limits.

    I’m guessing that the locations with enforcement do have some sort of cost benefit analysis with the costs being the equipment itself and casualties.

    But surely the cost of this type of equipment must have come in recent years down like most technology?

    Looking at a speed camera map around where I live, the locations only seem to be major arterials so is automated enforcement still not cost effective on roads with lower traffic volumes?

  103. Quinlet,

    It might surprise you to know that I am in practically total agreement on your last comment. The point I was specifically challenging was why the police should do this when they really have better things to do.

    I think a lot of this comes down to the practicality of things. Issuing a speeding ticket is not a five minute job and a police officer costs taxpayers roughly £60 an hour when all costs are taken into account. Before that is the issue of whether there is enough evidence that would stand up in court and whether the police can legally apprehend the suspect.

    For starters, the officer needs an independent method of verifying that speeding occurred (e.g. a speedometer in a police vehicle, CCTV or a colleague who also witnessed what happened). For another thing, drivers of police vehicles, if used, can exceed the speed limit themselves to stop the offending vehicle only if they are appropriately driver trained and most police officers that drive are not.

    Next comes the issue that officers acting independently can no longer issue Fixed Penalty Notices themselves if a driver is accused of speeding. He/she has to write a detailed report as to what happened and then that gets reviewed and if it is decided that it is appropriate and if all the relevant details have appeared to be recorded correctly then a Fixed Penalty Notice is issued (unless this would lead to a driving ban in which case a summons must be issued for a court appearance so that the magistrate can revoke the driving licence).

    Also, at the time of the alleged offence, it is policy to check other details at such as insurance and whether the person has a valid driving licence. If the police officer does not have a modern PDA then this all has to be done by radio – again this can sometimes be very time consuming. During this time the person is, for practical purposes, detained. If this is a long period then you start to bring in the human rights issue of proportionality if the offence was minor e.g. speed limit exceeded by a small amount.

    In reality it is far more practical to have pre-planned operations using a speed camera. One advantage is the evidence is hard to dispute in such cases. But these then get quite complicated. For example, they are pointless unless you have a “chase car” in case people don’t stop. This then means that you have to tie up two advanced trained traffic officers to sit in a car doing very little most of the time. Then, as I commented on before, you generally need to involve other organisations to get the best out of it.

    Next, you need masses of manpower to mount a speeding operation. Police Officers are taught that there is no such thing as a straightforward traffic stop. What it the driver winds his window down and the vehicle reeks of cannabis? What if the vehicle has to be seized? You only have to look at the fly-on-the-wall police programs to realise how long it can take to check insurance details. It sounds simple but a lot of the bad guys resort to various tricks to make it appear that they have valid insurance when they haven’t. And a lot of the good guys make an innocent mistake (such as women having insurance in their maiden name and their licence in their married name – or vice versa) that takes a long time to get to the root of the problem and sort it out.

    Finally, if you could see the outcomes of ANPR operations as opposed to speeding operations you would probably think that ANPR operations are a far better use of police resources. Why go looking for new, relatively minor, offences, when you can catch people who need catching for all sorts of reasons (including no insurance)? And people who do not have insurance are supposedly 250 times more likely to be involved in a collision than people who do have insurance. So ANPR operations that also check driver’s insurance are more consistent with the Mayor’s directive to reduce deaths and serious injuries on the roads than speeding operations.

  104. PoP ( & others )
    Heartily second PoP’s remarks re, ANPR operations as a very good use of resources & much more effective for traffic-safety & saving lives than “Catching Speeders”
    I’ve seen this in operation, twice, & was mistaken for a “Customer” on the first ocasion (!)
    Method:
    ANPR camera mounted on parked car, “watching” oncoming traffic … when uninsured (etc) vehicle shows up, computer flags it, officer in car radois mate a little further down the road …
    Who then indicates car to turn off into …
    Convenient large space, temprarily occupied by Plod, who then …
    Get driver out of car, demand particulars & usually search vehicle.
    There’s a back-up officer just a little further down the road if the marked car doesn’t stop, too.
    They usually have asteady stream of “customers”, and often at least one who isn’t going anywhere except the local nick ….

    Fun ensues, when “empty” space is a disused car-park that leads to our allotment gates & I drive in, without directions & the Land-Rover has 15 bags of horse-manure in it.!
    ( They decided that, no, I wasn’t a customer, & no they weren’t going to help me unload it, either….. )

  105. PoP
    What you say makes a great deal of sense within the rules that are set down. However, it does display a degree of bureaucracy in the issue of Fixed Penalty Notices that completely fails to exist within the Penalty Charge Notice regime. For example, why can’t a police officer issue a FPN on their own? Why does it need a further report? There may well have been instances in the past when mistakes have been made which a further check would have stopped, but there is a question of proportionality here. I entirely support the ANPR regime and I’m sure it does very good work. However, at the end of the day it remains the case that the enforcement of speed limits is not effective and either we should change the enforcement regime or change the speed limits.

    @Reynolds 953
    If it’s a box junction, the local highway authority is responsible, if it’s a speed camera then it’s the police.

    The distinction appears to be that the police are entirely responsible for all offences which have driver liability, as only they can get to the bottom of who was the driver at the time, either by stopping the vehicle or by asking a compulsory question. In turn this impacts on the sanction as anything involving penalty points must be driver liability. Highway authorities are only responsible where the contravention is keeper liability and where the sanction is only financial. This presumes that if the keeper was not the driver at the time, the keeper will either be able to get the driver to pay or they won’t be driving that car again.

  106. Quinlet

    why can’t a police officer issue a FPN on their own?

    That is what used to happen until a couple of years ago. It may still happen elsewhere. It was decided that having a police officer issue a FPN created a level of arbitrariness in that one officer would issue tickets having decided the threshold for issuing it was met and another would not do so.

    In order to create a consistent standard the decision to issue the FPN or summons is done by a back-office team who supposedly apply a common standard based on the officer’s notes. Maybe in future they will also review the officers’ body worn cameras.

    There is some logic behind this as even an individual officer may be inconsistent from day to day. Or he may decide, possibly subconsciously, that the individual involved has failed the attitude test – which, of course, is not a factor that should be considered when deciding on whether to issue an FPN or not.

    Of course, if speeding is so bad and reckless that it amounts to dangerous driving then it will be pursued with vigour. As much as anything else, this goes back to the Mayor’s policy of wanting to reduce the number of deaths and serious injuries.

  107. If there are consistent standards then they are either met or they are not met so long as those standards are objective. It shouldn’t matter who is considering them as the standards themselves ensure consistency. If the standards are not objective but subjective – that is, they rely on opinion or judgement – then a back office team will be no more consistent than an individual officer. Each team member may vary or be inconsistent from day to day. You say that the back office team relies on a common standard based on an officer’s notes, but there is a level of inconsistency in how each officer will write their notes. Thus an additional element of inconsistency has been built in in the name of securing consistency!

    Your last paragraph merely demonstrates the point that I have been making that the police make up their own minds about whether to enforce or not. The question is not about whether speeding constitutes dangerous driving, but whether it exceeds the posted limit. If it is not, then there is no point in having speed limits at all.

  108. Well, from what I read from the comments and replies between Quinlet and PoP, that reliance on a back office team to ‘substantiate’ a FPN/TPFN is both inefficient and surely can produce worse reliability in accuracy because they didn’t witness what actually happened as opposed to a Police Constable (“PC”) on the spot who did.

    It used to be until recently the requirement of a PC to ensure e.g. this: “A TPFN must give sufficient details of the alleged offence, together with details of the suspended enforcement period, the penalty payable and how it should be paid.”. Simples.

    I haven’t driven a car in London for many years but I always believed it was the duty of a PC to enforce traffic offences over and above those of e.g. traffic wardens, so for PoP to explain otherwise I suspect is something that the general populace is not aware of.

    Before my time, it was a PC who arrested a Croydon Corporation tram driver for running alongside his tram on Brighton Road (presumably after he rejoined his tram to stop it…), it was a PC in a car who was following my Dad’s car in Croydon and stopped him for exceeding the speed limit a little, and it was a couple of PCs who decided to stop me when I was driving home in my mother’s car to check the car, its contents and the fact that I had permission to drive it. All of these and similar tasks were carried out by PCs on duty on the street. If nothing else, it was a deterrent – far more than ever any fixed traffic sign is.

    These days, I see far more ambulances than PCs, whether in or out of their cars! They must all be penned in those back offices, performing classic jobsworth civil service jobs rather than where they probably hoped to be, doing a better job for all concerned out in the open air witnessing the offences first-hand. They could start with the numerous cyclists racing through red traffic lights all over the place at any point of the red phase, every day.

    Those back room staff are not readily going to catch or deter those who have been recently causing mayhem on mopeds, either.

    In Japan, the traditional PC on the beat system is rigidly followed, with a police station ‘box’ located at most major traffic intersections (think classic London Cab drivers’ shelter but updated and with big windows facing the road). This means that (a) the police are always in view on the street and (b) they can immediately summons assistance from the nearby police boxes.

  109. This is discussion is now going beyond the relevance to transport. I will reply to the points made by Graham Feakins and take the liberty of making some further points of my own and then I will delete any further postings that have strayed too far off a transport issue. If people want to discuss this then the pub on Thursday is a more appropriate place.

    Graham, very little has changed. FPNs always were reviewed. It is just that it was done after they were issued. If anything was out of order, to the extent that the FPN was incorrectly issued, then the FPN would be cancelled and any fine already paid would be repaid. That, presumably, takes more effort, by all parties involved, than not issuing it in the first place. What I would argue has changed, for the better, is that in all probability the FPN is now actually legible.

    You always did need back room staff – not necessarily always police officers. They need to ensure the money is collected and take the necessary action if it isn’t (fine contested or ignored). They probably need to double-check that the person had a right to drive the vehicle in question on that day as well. All stuff that can be done much quicker and easier in a quiet office with a computer in front of you and with a landline telephone available.

    I suspect nothing has changed as regards the written officer’s (PC, PS, SC, whatever) evidence. Other than, again, it is legible. And if the alleged offence is challenged then it is the constable who was present at the time of the alleged offence who has to stand up in the magistrates court and explain their actions with the assistance of his/her original notes made at the scene.

    The issue of an officer’s evidence is a critical one and one that can be a bit of a logistical problem for pre-planned operations. Imagine a spotter seeing someone on a mobile phone. He calls for the vehicle to be stopped. It is stopped a few hundred yards away (e.g. at Greg’s allotments). The person is no longer on their mobile phone and denies ever having been on it. The only way to prosecute is if the evidence of a police officer is available but the officer in question is busy checking subsequent ANPR readings and has probably already forgotten details of what he saw. The police have no powers to look at the mobile phone to prove a call was being made (and, in any case just using the device for any purpose is enough to create the offence).

    In my opinion, what is needed is a coming together of technology, legislation and procedures accepted by the courts to produce a practical, efficient and fair means of catching the worst offenders. If it can be done without involving police officers then so much the better. Better still, utilise the technology to prevent the offence occurring in the first place. We are going some way with this by having speed warnings that indicate your speed to try and encourage people to stay within the speed limit but more needs to be done in other ways to make best use of the technology now available.

    I would also add that these days the courts, quite rightly in my opinion, expect much higher standards of evidence than in the past. I suspect this is due to the technology around to make that evidence available. So one tends to want to go for the “cannot be disputed in court” type approach rather than have it simply being a case of one officer’s word against that of a member of the public.

  110. Jumping in late, I am not an expert but my lay understanding is that the conditions caused by pollution lead to an increasing reduction in the quality of life over many years before death so the impact of pollution on quality adjusted years of life is far far greater than the reduction in years which is in complete contrast to PoP’s guess that you should reduce the impact for the poor quality of the missing years. It is the same as for smoking which reduces healthy life expectancy by much more than ordinary life expectancy (irrespective of which of the many measures you use to measure impaired quality of life ). By contrast, road accident deaths have no impact on the quality of life before death.

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