THE Highways Agency will be testing the newly-installed smart motorway systems on the hard shoulder of  sections of the M4 from Tuesday tomorrow for a period of three weeks.

For the first time the hard shoulder will be opened up to road users, under trial conditions, for short periods during off peak times on the section of the M4 between junctions 19 and 20 at Bristol between 5 and 13 November.

Traffic officers at the Highways Agency regional control centre in Avonmouth will open up the hard shoulder to traffic, setting overhead messages and variable mandatory speed limits to indicate when drivers can use the hard shoulder as an extra lane.

Testing of the systems allows the Agency to check the technology is fully working ahead of full operation on this section of the M4. Subject to the trials and tests being completed successfully the smart motorway systems will become fully operational during peak traffic conditions on the M4 from the end of the month.

Highways Agency assistant project manager, Adrian Hull, said: "We urge road users to follow the overhead signs, and remind them that the hard shoulder can only be legally used by motorists as a running lane when a speed limit is displayed above it – otherwise it is for emergency purposes only."

Variable mandatory speed limits will be introduced on the M5 from Monday 11 November, following removal of the free recovery service. The electronic signs on the gantries above the carriageways will be used to display the variable speed limits between Junction 15 and 17. Testing of hard shoulder running on the M5 sections of this scheme is due to begin in December.

The enforceable variable speed limits will be indicated on the overhead signs above each lane in a red ring and will be introduced to help ease congestion during busy periods or if an incident occurs. Lane closures will be displayed by a solid red cross with flashing beacons and instructions to move out of a lane will be displayed by a white arrow.

Once fully operational, the £88m managed motorway scheme will cut congestion, make journey times more reliable, and improve safety through the use of variable mandatory speed limits, and ease congestion by opening the hard shoulder as an extra running lane during busy periods. 

For further information on the M4 M5 managed motorway scheme, visit www.highways.gov.uk/our-road-network/managing-our-roads/improving-our-network/managed-motorways.