Wednesday, 1 April 2015

Can cycling superhighways give wider benefits?

Martin Gibson - Head of Operations

This month, Boris Johnson launched the start of construction of London’s new North-South segregated cycling superhighway. The route will run from King’s Cross to Elephant and Castle and is part of a package of measures that is hoped to further boost cycling in London. It will be followed fairly soon by a new East-West Superhighway from Tower Hill to Westbourne Terrace. The new routes will extend the superhighway network into and across central London.

A lot of other cities are also trying to dramatically increase cycling. Manchester is looking to develop cycling along the Oxford Road, closing it to car traffic. Edinburgh is trialling a segregated cycle lane along George Street. Cambridge is putting in segregated cycling lanes on key routes.

One of the reasons for increasing cycling is to drive environmental improvements, especially in air quality. Transport for London published its Environmental Evaluation Report for the new cycle superhighways in January. This predicts route wide benefits and no adverse route wide effects. The report shows that there will be both positive and negative local environmental impacts from the proposed new cycle superhighways. The positive effects considerably outweigh the negative effects, with air quality and noise due to improve in a number of locations.

The study behind the report shows that changes in traffic will re-distribute vehicle emissions but will not increase overall emission levels. It does not mention the possibility of an overall reduction in emissions on a wider scale. However, work in the late 1990’s showed that reducing road capacity can sometimes lead to traffic effectively disappearing. If this were to happen, then the cycle routes should lead to a wider improvement in air quality.

From the scale of highway capacity reduction that the new cycle superhighways will produce, it seems possible that traffic could reduce. If it does, this should lead to improvements in air quality and reductions in noise that are significant enough to be considered more than just local. If evidence emerges that there are wider air quality benefits, it should provide more impetus for innovative projects that are currently on only at the concept phase. In London alone, these include a Norman Foster’s sky cycle, the London Underline and the Floating Track on the Thames.

It may be hard to disaggregate the effect that the segregated cycle highways will have on London’s environment but it will be important to see if air quality improves when they are completed.