Abstract
The present paper reports about a recent study carried out in the Netherlands about optimal speed limits of passenger cars. The structure of this paper is as follows. In Section 2 a number of concepts of speed is introduced which are relevant in discussions about speed limits. The models used to analyse the impacts of speed limits are presented in Section 3. The features of a cost-benefit analysis of speeds and passenger cars are presented in Section 4. In Section 5 empirical results are presented for the Netherlands. Section 6 concludes.