Peter Jones

The problem Jones solved is one of classification. Traffic engineering ranked streets on a single scale, from motorway to cul-de-sac, according to how many vehicles should pass. That scale has no slot for what many streets also are: a place where people shop, sit, wait, play and meet.

His proposal, developed with Natalya Boujenko and Stephen Marshall, is to use two scales at once. Every street has a link value, how important it is for moving across the network, and a place value, how important it is as a destination. They cross in a matrix, and each cell calls for a different design. A neighbourhood shopping street with high place and low link requires the opposite of an urban ring road. What matters is that the method lets a decision that previously looked like an opinion be justified technically.

A professor of transport at University College London, Jones has spent half a century working on traveller behaviour, public participation in transport decisions and policy appraisal. He was one of the promoters of survey methods that ask about a person's whole day rather than an isolated trip.

His other contribution is the model of three stages European cities pass through: first adapting to the car, then managing demand, and finally rethinking the street as urban space. That framework, developed in the European CREATE project, lets a city know which phase it is in and which measures make sense, and explains why simply copying what Amsterdam did usually fails.