Paul Mees, of the Royal Melbourne Institute of Technology, has written an interesting book entitled Transport for Suburbia, in which he makes a persuasive case that public transport can be viable in low density suburbs.  ‘Density is not destiny’ is his maxim.  The book contains an extensive compilation and analysis of public transport systems, particularly where these have been successful as in the city of Zurich where in 2000 66% of commuters travelled to work by this means, compared with 19% by car. 

Mees’s central idea is that there is a ‘network effect’ for public transport systems which knit routes and modes together into a single multimodal network, with near effortless transfers between routes by means of timetable coordination and through ticketing. Network effects are well recognised as a positive externality, originally for the telephone system where the more users there are, the greater the value for each user.  To achieve a public transport network, which is a natural monopoly, there needs to be a public agency for tactical multimodal planning.  A competitive system will not secure these economic gains. 

This perspective is illuminating in the UK context, where public transport in London has thrived under the oversight of Transport for London, whereas in most of the rest of the country bus patronage has steadily fallen.