Paul is a geographer in the School of Science at UNSW Canberra, Australia. His highly cited research has made a pioneering contribution in the areas of child-friendly environments, active transport, and healthy and sustainable cities. These themes are brought together in his 2020 book written with Rodney Tolley – Slow Cities: Conquering our speed addiction for health and sustainability. This demonstrates, counterintuitively, that reducing the speed of travel within cities saves time for residents and creates more sustainable, liveable, prosperous, child-friendly and healthy environments.