Since the end of the 1980s quite a number of automatically actuated traffic control systems have been in use on freeways in Germany. In the 1990s the German Federal Ministry of Transport, Building and Urban Development pushed their implementation providing a considerable budget within a framework programme. Against this background the question has come up which costs and benefits such systems carry in the course of their life cycle. Therefore, the present study aimed at showing how such cost-benefit ratios can be assessed more precisely when taking into account the whole life cycle of a traffic control system. A survey among the operators of such systems was undertaken to inquire the costs incurring during these different phases. It turned out that there are major differences between the individual system types regarding the costs distribution onto the individual phases. The benefit calculation was based on methods and models already developed in other research projects and relevant working committees of the Forschungsgesellschaft fuer Strassen- und Verkehrswesen (FGSV). The cost rates and benefits determined serve as a basis for life cycle tools. These life cycle tools provide for an overall assessment of any traffic control system over its entire life cycle. They incorporate the Excel tools developed by TU Munich. To calculate the effectiveness of systems for the temporary opening of hard shoulders the AVP program was used. Applications of the tools to three sample systems have revealed that costs and benefits calculated over the entire life cycle of a system lead to higher cost-benefit ratios than cost-benefit analyses carried out on the basis of conventions so far agreed. With the developed life cycle tools for traffic control systems the users have been provided a set of instruments which they can use to carry out a cost-benefit assessment over the entire life cycle of the respective type of system within a few minutes. (Author/publisher)
Samenvatting