Andre Gorz in 'The Social Ideology of the Motorcar' says 'Above all, never make transportation an issue by itself.'

I keep hearing it said that building an underground public transportation system would be hugely expensive, and Cambridge is too small.

Cambridge is not small. There are a third of a million people who live in greater Cambridge, and that doesn't even consider the many people who live in Fenland, Huntingdonshire or elsewhere and who commute into Cambridge.

However, there was a study that looked at the cost of tunnels for public transport and it came up with a very simple number.

Robin Heydon, Chair of the Cambridge Cycling Campaign

The lifetime cost of a subway in Europe is £7,000 to £17,500 per rider. This is not the usual metric that people like to use. Most people will be given metrics like the cost per kilometer, or the total cost of a tunnel project.

I'm sure some people will look at those numbers and think that this is a huge subsidy. Yes, you can think that, but if you do, then I'll remind you that the £1.6bn widening of the A14 is only designed to move an extra 20,000 people a day, a subsidy of £80,000 per 'rider'.

Today we have about 44,000 people commuting into Cambridge every day, and therefore, as they probably go home at night, a ridership of about 88,000 people. With employment growth, this may rise to over 150,000 trips a day in and out.

If we did the radical thing and encouraged people out of those private motor vehicles and onto an underground public transportation system of some kind, we should be able to capture a good 50 per cent of these commuters. That is a ridership of 75,000 people a day. That would, if we benchmark this against other European projects, mean a budget somewhere between £0.5bn and £1.3bn. So the project would cost less than the A14 widening, and provide significantly more benefits for a lower subsidy or cost per user.

The benefits of doing this would be more than just having one of the cheapest ways to move people into the city, and to their jobs, but it would also free up space on the roads for other uses.

The problem I have with all these transport projects is that they always measure the cost of doing something, but they never really quantify the benefits to everybody else. Removing lots of motor traffic from the inner city centre would have a transformative effect on those areas. I'd love to see street cafes spilling onto East Road, a connection between the commercial areas of Burleigh Street and the residential areas around Norfolk Street. Parker's Piece would become a quiet park that people would flock to, rather than a noisy and smelly bit of green sandwiched between a bus stop and a carpark.

Cambridge is special because of all the green space in the city, and because these green spaces link out to the edge of the city and beyond. These are spaces that are fantastic to walk and cycle though.

We need to make the main roads also green and pleasant places to walk and cycle along. If this means that we need to move the main public transportation system underground, then this may be a price worth paying, so that we can gain the benefits.

