A new convoy control method of traffic management is being piloted on the M40 near Oxford this week.

The Highways Agency is testing a new way of slowing down traffic which is designed to improve safety for contractors carrying out roadworks.

High visibility contractors' lorries will travel on the carriageway three abreast, reducing speeds to 30mph for a few minutes to create a short gap in the traffic in front of them.

Short trials started this morning, between junction eight, near Wheatley, and junction 10, by Cherwell Valley services, and will continue overnight on tomorrow and Thursday.

The scheme is being developed by the agency for situations when contractors need to close lanes in busy traffic.

Annie Harris, Highways Agency spokesman, said: "When we are putting traffic management out we have to have the safety of the workforce in mind."

Drivers will be alerted by warning signs on the rear of the lorries showing a red cross and the words "convoy control -- no overtaking".