Roberts was one of the pioneers of sustainable transport planning in the United Kingdom. He was one of the first to introduce the idea of traffic calming from continental Europe. Roberts founded TEST in 1972 and led over 150 projects resulting in reports, books, and papers. He advised both Prince Charles and John Prescott amongst others
Prior to founding TEST, Roberts worked as an architect for the Greater London Council, Oxford Polytechnic and Llewelyn-Davies Weeks.