Summary, Conclusions and Future Research Directions

Congestion affects most metropolitan areas around the world and has a strong negative impact on the economic activities. The traditional tool to tackle the congestion problem is to build more road infrastructure. However, the feasibility of this instrument is nowadays regarded to be rather low, as the social and environmental costs of enlarging the existing road infrastructure might exceed the economic benefits. As a consequence, transportation research is placing more emphasis on using existing road networks more efficiently. The research presented in this book analyses two instruments that have the objective to increase the road network efficiency: motorist information systems and road-pricing. These instruments have recently been gaining much interest, as there is a strong belief among academics and practitioners that motorist information systems and road-pricing are the main ingredients of a future government policy that aims at curbing levels of congestion in an effective and efficient manner.