See the M4 smart motorway plans before work starts this autumn
The Smart Motorway upgrades on the M4 will run from Theale to Hayes in West London
Plans to convert stretches of the M4 into a Smart Motorway are to be displayed at a number of public exhibitions.
Highways England will be converting the M4 from junctions 3 to 12 into a smart motorway this autumn.
The smart motorway section will run from Theale in the west, past Reading, Berkshire, all the way to Hayes in west London.
Smart motorway conversion involves turning the hard shoulder into a permanent fourth lane, the introduction of variable speed limits and employing fast reacting road signs to inform motorists of developments.
Highways England states: “Smart motorways are a technology driven approach to the use of our motorways, increasing capacity and relieving congestion while maintaining safety.
“Smart Motorways help make journey times more reliable, at less cost than traditional widening schemes, meaning better value for the tax payer.”
In terms of safety, new emergency areas will be built into the carriageway to replace the hard shoulder.
There will be a telephone in each emergency area, which will connect drivers to Highways England’s Regional Control Centres that will be able to pinpoint the location of the emergency.
Smart motorways have already been introduced on the M3 and in several other stretches of motorway across England.
The scheme to convert the M4 was approved back in September 2016, and Highways England has been planning the implementation of the project ever since.
Work on the project will begin in September 2018 and is expected to finish in spring 2022.
The building project will involve four key components:
- Converting the hard shoulder into a fourth lane – where the hard shoulder is not in place, a new lane will be built.
- Building “through junction running” which enables a consistent number of lanes to pass through the junction, reducing the need to change lane for vehicles staying on the motorway. Through-junction running will be in place at junctions 4, 5, 6, 7, 8/9 and 11 and at the Reading motorway service area.
- Bridge works, which will mean that 11 bridges will have to be demolished and replaced, four bridges will need widening and subways under the motorway will have to be lengthened.
- Building of the new Emergency Areas.
How will work be undertaken?
During construction, Highways England will set up a number of construction compounds to administer the roadworks.
While the work is taking place, narrow lanes and reduced speed restrictions will
be put in place “to create a smooth and safe flow of traffic through the works and to protect workers”.
Highways England adds: “Additionally, traffic management barriers will be needed. Three narrow lanes will be available for road users during peak hours.”
To minimise disruption, noisier work will take place during daylight hours.
Core work will be administered from 8am to 7pm on weekdays (excluding bank holidays) and from 7pm to 4pm on Saturdays.
Overnight closures will be required at times and these will be fully advertised and diversion routes put in place for those using the roads at these times.
What about the bridges?
Extensive work will be undertaken on many of the bridges between junctions 12 and 3.
Highways England states: “Much of the M4 was originally built as a two-lane dual carriageway, and has been upgraded over the years.
“Eleven bridges over the motorway need to be replaced to make room for a new lane where there is no existing hard shoulder.
“To limit local disruption, new bridges will be built next to the existing ones, before the old one is demolished.
“However, where there is not enough space for this, some bridges will be demolished first, then a new bridge built in the same place.
“Where the motorway passes over, for example, the River Thames at Bray and the railway line to Windsor, we will need to widen structures to support the new
The work will require weekend closures of the motorway to be completed, information for that will be advertised on the Highways England website.