In this paper, we investigate congestion caused by differences in desired or possible speeds. Especially outside peak hours, speed differences are probably one of the most important reasons for congestion. Although the model setting, with one lane and no overtaking, may seem simple at first...

This paper studies some of the properties and fundamentals of static models of road traffic congestion that have triggered much debate in the literature. The first part of the paper focuses in particular on the difficulties arising with the backward-bending cost curve in the context of...