City lights: regulated streets and the evolution of traffic lights in the Netherlands, 1920-1940

This article looks for patterns in the development of traffic lights in the Netherlands in the 1920s and 1930s. In order to analyse these patterns the metaphor of quasi-evolutionary development is used. This theory of technological development, with variation and selection as its key terms, is well known to historians of technology. The article answers the question why between 1926 and 1934 traffic lights in the Netherlands emerged in a broad variety of forms and different combinations of colours, and why in the mid-1930s this rich variation was reduced to the three-colour standard we know today.