Raising the cost of driving in London through congestion charging means more people than ever now use other forms of transport to get around town. Research published today suggests an unintended side-effect – a rise in motorcycle casualties.

Dr Robert Noland from Imperial College’s Department of Civil and Environmental Engineering has co-authored a report showing a rise of 40 motorcycle casualties per month in central London during the hours of congestion charging. By contrast, the number of motoring casualties has dropped by 5.6 per month.

The effects seem limited to central London – figures for Greater London show no statistically significant change.