Based on our study of Turkish rail construction, we found that there were four primary factors that kept construction costs low and the processes efficient. First, there was an ongoing political commitment spanning different administrations to build an extensive rail network in Istanbul. Second, through years of construction experience, initially learning from foreign experts brought in to consult and train the Turkish teams, and later collaborating with Turkish contractors and consultants who were now building rail all over the world, the agencies gained the capacity to streamline processes and manage projects efficiently. Third, market competition encouraged contractors and consultants to lower their costs, while developing their technical and technological capacities. Fourth, all parties involved quickly learned that speed saved money, and evolved their processes to avoid unnecessary delays. Ultimately, these conditions cultivated a competitive, agile and competent rail sector.
Throughout the last 20 years, the IMM has developed know-how and optimized its procurement processes to better manage rail construction projects. On the other hand, the AYGM under the central government has recently hired former IMM personnel as AYGM has begun to manage more projects in Istanbul. Since 2014, the IMM has utilized “final design for application” projects that are at 60% design, which has helped it go to construction tenders with more detailed information and better control over projects. In the earlier projects where the agency was still figuring out how to build subways, they would go to tenders with an underdeveloped preliminary design, leading to higher costs due to overdesign overseen by the contractors, as was the case for M4 and earlier projects. By the time the agency started working on M5, it knew enough to specify better optimized station and tunnel designs. The contractors we interviewed agree that this was one of the major changes that improved rail-construction processes; over the last 15 years, the agency has learned to spend more time on the design, working with experienced design consultants, prior to the construction tender.