The UK Government Office for Science is running a Foresight project on the Future of Cities. I was asked to contribute an essay, the key points of which are:
- Successful cities are characterised by growing populations as people are attracted to work, study and live. As population density increases, agglomeration effects contribute to economic productivity and to similar cultural and social benefits.
- Increasing population density precludes enlarging the road network to accommodate growth of car-based mobility. Instead, rail systems must be expanded to provide fast and reliable travel for those who work in the city. So the share of journey by car declines.
- In London, car use peaked at 50 per cent of all trips in around 1990. It has now fallen to 37 per cent and should fall further to 27 per cent by mid-century, on the basis of current projections and policies. This will make a significant contribution to mitigating transport greenhouse gas emissions.