It is not uncommon for a metro construction tender with a scope involving over 10 kilometers of tunnels to receive six or more bids, even when there are several lines under construction at the same time. The intense competition for metro construction encouraged contractors to innovate and bring their prices down. Contractors are motivated to win bids because there is a clear pipeline of new metro projects and many have invested in technology and expanded their equipment pools. Since 2014, Building Information Modeling (BIM) has been used in design, planning and management of construction, and it has been mandated through the agency’s contract specifications. Design consultants, construction managers and contractors rapidly adapted to the new requirements and all attribute their improved coordination and more efficient management of projects to BIM solutions. In addition to greater competition amongst general contractors, it is also now easier for contractors to buy or rent construction equipment, which reduces costs. Many contractors own TBMs, and keep costs low by utilizing the same machine on multiple projects. They also understand the specifications of the equipment better, and therefore can buy TBMs suitable for different soil conditions rather than changing cutter heads during construction, which slows down the pace of tunneling and adds costs.
The agencies, contractors and consultants understand that speed saves money. The Environmental Impact Statement (EIS) certification and preliminary approval processes are rapid, and the contractor starts excavating as soon as the project’s rough boundaries, such as station exits and entrances, are determined. The contractors obtain pre-approval to start excavating before the designs are 100% complete and break ground, even though this sometimes means needing to do revisions. A senior manager we spoke to attributed Istanbul’s speed and lower costs to the Turkish teams’ ability to think outside the box (Personal Interview I 2020). The contractor and the agency develop quick solutions for problems that come up and find ways to work within the plans, standards and regulations. So the project ends up changing a great deal throughout the construction process, but is completed within the planned budget, or with the 20% allowable cost increase, and fast, relative to other countries in our database.
A steady stream of projects, competition between the IMM and the Central Government’s Ministry of Transportation, as well as a robust pool of contractors vying for work has cultivated a productive rail-construction ecosystem in Istanbul. This benefits the city, even in cases where a contractor lacks experience, the agency, consultants, subcontractors with years of experience in the field along with the now established procurement mechanisms can make up for these shortcomings by helping the contractor learn on the job and deliver projects with minimal delays and cost overruns.