The 20mph transformation programme

The council is rolling out 20mph areas as a replacement for 30mph areas where there is local support

As part of the County Council's commitment to ‘Vision Zero’ (the elimination of deaths and serious injuries from road traffic collisions in Oxfordshire) communities are able to request the introduction of 20mph areas. In February 2022, Cabinet approved funding of up to £8,000,000 to deliver 20mph, meaning the implementation of schemes comes at no cost to town or parish councils. The initiative is not compulsory however the greater level of coverage we attain across the county the greater level of compliance we will gain.

The authority will support measures from a simple change of speed signs to more complex engineered solutions in areas that can range from a whole village or a single street. The authority will not provide speed cameras or traffic calming, such as road humps, as part of the programme (although Parish and Towns can fund this if they wish).  Officers will work with local bodies to establish the best methods for ensuring compliance within their areas.

The introduction of 20mph in our 2021/2022 pilot areas has already reduced speeds by up to 4mph.  This has really benefitted the local communities and it will help to reduce the frequency and severity of accidents.

Which areas are eligible?

To be eligible for 20mph a scheme must

  • be supported by the local town or parish council and the local County Councillor


  • be within the extent of the built-up environment of the town or village where vulnerable road users and vehicles mix in a frequent and planned manner


  • have an existing speed limit of no greater than 40mph


  • be in an environment that explains and justifies a lower speed limit to the driver.

Read a full set of guidance (pdf format, 12Kb) for application criteria  If you would like to discuss a potential 20mph application, please contact the 20mph team via

The benefits of 20mph

Safer roads

Research by the UK Transport Research Laboratory has shown that every 1mph reduction in average urban speeds can result in a six percent fall in the number of casualties. It’s also been shown that you are seven times more likely to survive if you are hit by a car driving at 20mph, than if you are hit at 30mph. If a child suddenly steps in front of a car, you are much less likely to seriously injure or kill them if you keep to a 20mph limit.


Research shows that slower speeds encourage a smoother driving style with less stopping and starting, which helps traffic to flow. Evidence from other areas shows that slower speeds encourage more people to walk and cycle.

Air pollution

Driving at 20mph causes some vehicular emissions to rise slightly (mainly Heavy Goods Vehicles) and some (car) to fall. Reduced acceleration and braking will help to reduce fuel consumption and the associated particulate emissions from items such as tyres and brakes.

Little impact on journey times

Research in other cities, suggests that journey times do not significantly increase.  Where proposals are requested on a bus route the authority will work with the bus companies to assess the likely impact on bus journey times to enable a balanced approach to be taken. 

Monitoring the zone

The council are carrying out a variety of ‘before and after’ surveys as part of the monitoring programme for the 20mph network which will be assessed a year after the completion of phase. Key ‘representative’ locations will be selected and findings will be published on this webpage.  Further monitoring will be undertaken in 2024, 2025, and then again in 2029.  This will enable the authority to get a balanced overview of this programme's benefits to our communities

Can a scheme be removed if it doesn’t work?

Yes - If the scheme is deemed as not working, then we can consider removing or amending it.

How motorists will know they are in a 20mph area

Signs and lines will be installed in line with the relevant traffic and road safety traffic signs manuals.

A county-wide marketing campaign will ensure that if a new area is changing to 20mph local residents are informed in advance.

20mph signs will mark the entrance and exit of a 20mph area where the speed limit changes. Smaller repeat signs and or road markings will supplement these signs.

Drivers of any vehicle should drive according to the Highway Code and as such, they should be aware of the speed limit they are currently in.