Draft Department for Transport document also says “significantly lower speeds usually desirable” in new residential areas
New and redesigned residential and urban roads should get 20mph rather than 30mph speed limits by default, guidance from the Department for Transport has recommended.
A draft version of the DfT’s ‘Manual for Streets’ planning document, seen by the Sunday Times, says that “The default should be to work to a design speed limit of 20mph in urban environments”, and that “for residential streets, a maximum design speed of 20mph should normally be an objective, with significantly lower speeds usually desirable”.
The document is due to be published later this year, and follows a trend that has seen many areas in London set 20mph as the default speed limit on residential roads, with the Welsh government implementing a similar policy from September 2023.
Road bosses are keen on 20mph zones for the safety benefits they are perceived to bring, with research indicating that 5% of pedestrians hit at 20mph die, compared to 50% at 30mph. Other studies have indicated that a 1mph drop in average traffic speed correlates with a 5% to 6% drop in injury-causing collisions.
Lower speeds also bring with them less noise from tyres and the airflow disruption caused by moving vehicles, potentially improving the quality of life for residents.
Speed-limit compliance for 20mph roads is almost non-existent, however, with Government data showing 87% of cars exceed them when traffic is free-flowing, compared to 49% compliance for 30mph zones.
A spokesperson for the DfT told the Sunday Times: “There are no plans to introduce default or national 20 mph speed limits in urban environments. We have always encouraged road designs that enable low speeds to prioritise safety. It is for local authorities to consider setting 20 mph speed limits on streets where people and traffic mix.”
The RAC, meanwhile, cautioned that default 20mph zones bring with them requirements for enormous behavioural change, explaining: ““Every single person who took their driving test in this country was taught that it’s 30mph in a built-up area. If you are going to change that, don’t underestimate the extent to which you’re going to have to make sure you’ve told them, whether by signs, advertising or news coverage.”