Links to other TRL Websites

Popular Links

Latest Content

Current Projects

Snap poll

Stay informed

Discover more about TRL by signing up for news

You’ll receive alerts about world-class reports and real world trials on a wide range of transport, mobility and infrastructure topics. You’ll know when we publish market leading research, unique insights, and fact based analysis.

Be the first to hear our opinion and insight on the future of transport.


Sign up to participate in research about use of UK roads and new vehicle technologies

The results of our research inform government policy, the development of standards, and good technology design.

You may be invited to use our vehicle simulator at Crowthorne, or to use your own vehicle on the road, or simply to complete a survey.

Every trial is different, and provides essential evidence to advance our understanding.

At the heart of everything is our mission to improve safety: your contribution is essential.

Get in Touch

Have a question? Speak to one of our experts today

From the Archives

January 2005

Speed control and incident detection on the M25

A Controlled Motorways scheme was introduced on to the M25 in August 1995 from Junction 10 to Junction 16. This report presents an overview of the monitoring work undertaken by TRL for the Highways Agency between 1995 and 2002 describing the trends in traffic behaviour on this section. It also presents the results of a driver opinion survey, which provided a detailed understanding of how the Controlled Motorway was perceived by its users. The results of investigations into the effects of the variable speed limits on accidents, noise and air pollution are presented.

Learn More