Professor Juan de Dios Ortúzar currently works for the Department of Transport Engineering and Logistics, Pontificia Universidad, Chile. He has over 30 years experience as an academic and advisor on transport modelling and social project evaluation. He has fostered the development of discrete choice models and its application to determining willingness-to-pay for reducing transport externalities.

Luis G. Willumsen currently works as Technical Director for the transport planning consultancy Steer Davies Gleave in London. Luis has over thirty year of experience as a consultant, transport planner and researcher with a distinguished academic career. As an Information Technology specialist Luis has been involved in research into electronic toll collection, image processing techniques, incident detection, computer-assisted design of roundabouts and the development of expert systems for bus priority schemes.