Public transport that works gives people the ability to avoid road congestion and save valuable time. Fast and frequent public transport doesn't just help public transport users - it also helps to lower traffic volumes so road users benefit too. The best predictor of traffic speeds is the speed of the next best alternative. The surest way to beat traffic gridlock is to provide fast and frequent public transport.




Studies have shown that road traffic volumes build up and speeds slow down until it matches the speed of public transport alternatives. If road traffic slows down any more than public transport, people switch to public transport and ease pressure on the roads, allowing traffic speeds to increase again.

If public transport is slow, traffic must slow down a long way before people are tempted to switch from their cars to public transport. The graph below shows the result of one study demonstrating how road traffic speeds converge with public transport speeds.


Chart: Comparison of journey times by car and public transport

Note: This study showed that road traffic speeds and the speed of public transport ended up about equal since further slowing of road traffic speeds would result in road users switching to public transport and easing pressure on the road.1


Public transport that works offers fast journey times, so people are tempted off the roads before traffic speeds slow down to a crawl. Tell your MP that we need public transport that works so we don't waste so much time on congested roads.


Footnotes:

  1. David Lewis and Fred Laurence Williams (1999), Policy and Planning as Public Choice: Mass Transit in the United States, Ashgate, Aldershot