The benefits of projects designed to improve traffic conditions in congested road networks are often interdependent. This means that the benefits of one project may depend on if and when other projects are implemented. In the Oslo region a large scale investment program for the main roads will be undertaken during the next 15 years. This raises the issue of which projects to include in the program and how to phase the projects in. A major study is undertaken to investigate this problem. It involves grouping together projects that are interdependent and calculating net benefits for each combination of projects in a group. The benefits are calculated with a traffic assignment model that distributes an o/d matrix of vehicle trips on the road network according to the user equilibrium principle. Four matrices, representing different traffic situations are assigned for each combination of projects. Preliminary results indicate that the approach taken will be worthwhile, even if it requires a major effort and the total computer time will run into hundreds of hours. Japanese Ministry of Construction and OECD/Road Transport Research Programme held the seminar on "future road transport systems and infrastructures in urban areas" in Chiba, Japan on 4th - 6th june 1991 sponsored by the Japanese organizing committee.
Abstract