Does building new roads reduce congestion? Polis member Sustrans contributes to the “Transport Fit for Future Generations” report.

A report on alternatives to investment in the M4 motorway in South Wales came out last week. Polis member Sustrans made a significant contribution to the research alongside the Centre for Transport Studies at the University of the West of England and the New Economics Foundation to think through some of the possible alternatives.  The report looks at transport investment that supports alternative modes that could prove to be a win-win solution to increase the capacity and improve the flow of traffic for all travellers.

The report argues that the investment in public transport, active travel and the finalisation of the South Wales Metro could cost less and be more effective than building additional roads for the M4 corridor around Newport in South Wales.

The reports suggests to consider all possible options when it comes to deal with congestion problems. However, what emerged is that the main solution considered was the construction of additional roads segments.

“There is a great deal of evidence to suggest that road building just generates more traffic, so the congestion issue doesn’t go away”, Andy Cope form Sustrans says. The study underlines also that a lot of the traffic that makes the M4 congested is the local traffic making short trips. If those travellers were offered different options they would use public transport, walking and cycling facilities.

Read the full report here.


Sustrans is a leading United Kingdom charity enabling people to travel by foot, bike and public transport for more of the journeys that we make every day.  Sustrans collaborates with Polis member authorities in the UK on practical measures to promote healthy and sustainable travel choice, and with the Polis Brussels team on input to policy. More info here.