Motorists will be given up-to-the-minute information about journey times on the A414 in Hemel Hempstead as part of a pilot scheme by Hertfordshire County Council.
Variable Message Signs (VMS) will be used to display travel times and information on delays and congestion between junction 8 of the M1 and the town centre.
The scheme will run for a trial period of two weeks, starting on June 2, from Monday to Friday between 7am and 7pm.
If the trial is a success, it may be extended to other routes.
Terry Douris, cabinet member for highways and transport at Herts County Council said: “We want to make the most of the VMS technology to get messages to drivers at critical points on their journey and minimise congestion.”
Messages will be shown under the headings of congestion, delays and long delays.