Variable speed control: state-of-the-art and synthesis

In its policy to fight congestion, the Dutch Ministry of Transport in 1996 launched a program of measures, called Samen werken aan bereikbaarheid (go-operation for accessibility), to be implemented in the short term. In this program, special interest is directed towards a group of measures in the area of dynamic traffic management. One of these measures is the dynamic control of speed limits on motorways. In addition, variable speed control on motorways has also attained interest as a measure to improve traffic safety and reduce environmental pollution. In order to achieve the required short term implementation of the variable control of speed limits on motorways, the ministry has set up a three stage plan. The respective stages of this plan are: investigation of available knowledge; pilot application; and implementation. This paper presents the results of the investigation stage - the state-of-the-art of variable speed control on motorways.