Within the framework of Thai-German Technical Cooperation the first comprehensive Bangkok Transportation Study, BTS (Kocks, 1975) during the 3rd Plan in 1971. Major recommendations of the study included the construction of mass transit and expressways under a public transport oriented policy that included the restriction of car ownership/use, and polycentric developments around the city.
Unfortunately, there were major alterations from the plan favoring schemes with high economic and financial viability, and only the expressway through the heart of Bangkok has been implemented. With no real city master plan, no land use plan and no proper road hierarchy, the built-up area has undergone an uncontrolled linear expansion, causing severe traffic problems which remain a problem for the city until today. Furthermore the assumptions the BTS made – for example concerning population growth and traffic development – were rather inaccurate and did not match the real development in the city during the years/decades following the study.