The variable speed limit on the M4 around Newport should be removed and replaced with a permanent 50mph limit.
The commission recommends an average speed zone, with a fixed 50 miles per hour limit, stretching from Coldra (Junction 24) to Tredegar Park (Junction 28).
The change is one of three ‘fast-track’ measures recommended by the South East Wales Transport Commission.
The commission was set up by Wales’ first minister, to find alternative solutions to improving traffic flow around Newport after he pulled the plug on the M4 relief road in June.
The commission recommends:
- Scrapping the variable speed limit zone in favour of a fixed 50mph average speed limit.
- Preventing last-minute lane changes on the approach to the Brynglas Tunnels.
- Widening the role of traffic officers in responding to, and clearing, accidents.
The commission’s proposals will now be passed to Welsh Government ministers, who will decide if, and when, to implement them.
The current variable speed limit zone was activated in 2016, comprising a series of electronic signs which can be set independently to different speed limits.
According to GoSafe, the Welsh road safety partnership, the idea behind the current scheme is to keep traffic flowing, even at peak times.
But the commission found that the variable speed limit “often leads to a breakdown of flow on the M4 around Newport, especially on the approaches to the Brynglas tunnels”.
While the variable cameras work well during quieter times of the day, the report adds, they have had a “limited impact” on improving traffic flow during peak times, and can cause “harsh” accelerating and braking from some drivers.
A fixed average speed limit of 50mph, the commission proposes, should “reduce driver confusion” and encourage motorists to stick to a more consistent speed.
The report also recommends measures to reduce the number of lane changes on the westbound approach to the Brynglas Tunnels, when three lanes become two.
Improved lane markings and road numbers painted on the tarmac, as well as bollards to prevent drivers making last-minute lane changes, could improve journey times.
The commission also says traffic officers, who patrol the M4, could play a more significant role in clearing accidents – especially on stretches of the motorway where there is no hard shoulder.
The report recommends reviewing traffic officer response times and making sure each officer carries all the equipment needed to clear a crash or incident.
Wales’ transport minister Ken Skates said he was “grateful to the commission and appreciate the urgency they have shown in proposing these early practical steps, which are designed to make an immediate impact on traffic flow”.
He said the commission’s work would complement existing Welsh Government projects such as the South Wales Metro.
“These measures will need to be complemented with improvements to the wider transport network, particularly on our railways,” Mr Skates added. “That work is already well under way, and I am committed to going further still to ensure we tackle congestion and improve connectivity across the whole region.”