He studied at the Bartlett School of Architecture, University College London and practiced as an architect for several years, before seeking a change in direction.
He completed a PhD on transport, planning and environmental issues in 1970 at the University of Edinburgh,[2] without a scholarship and supporting a young family with his wife Heidi Krott.
[4] Hillman believes that public policy should be more socially and environmentally conscious, and is an animated speaker on a variety of topics, in his later years completing two books and promoting action on climate change.
Hillman is a lifelong cyclist, arguing against compulsory helmet laws in 1992, and in favour of cycling's health promotion possibilities in a British Medical Association report in 1992.
[5] He has argued that governments have failed to implement the policies required to achieve global zero carbon emissions and it is "now too late", but he still recommends individuals to become vegan or vegetarian, not own a car, stop flying and limit the size of their family.