Particulate matter pollution and 20mph limits

MQT on 2016-10-19
Session date: 
October 19, 2016
Question By: 
Caroline Russell
City Hall Greens
Asked Of: 
The Mayor


According to new research from Kings College 'Did policies to abate atmospheric emissions from traffic have a positive effect in London?', braking at 20mph produces half the particulate matter from tyres, brakes and the road compared to braking at 30mph. Given there is no safe exposure level to PM2.5 particles, should Transport for London (TfL) factor these findings into their decision-making processes around a) whether to implement new 20mph limits on the TfL road network and b) where to locate them?


Answer for Particulate matter pollution and 20mph limits

Answer for Particulate matter pollution and 20mph limits

Answered By: 
The Mayor

Improvements in air quality is one of the benefits I expect to see from implementing new 20mph limits on London's roads, along with fewer people injured and increased levels of walking and cycling. That is why I committed in my manifesto to expand the number of 20mph limits across London, including the TLRN.

TfL is trialling eight 20mph routes on the TLRN, over a period of 18 months. Changes resulting from introducing 20mph limits are being assessed against a number of criteria including air quality. This data will be used to inform the future programme of 20mph limits in London.