Big changes to ring road roundabouts proposed in £30m scheme

June 28 2021

The Siston Hill roundabout in Mangotsfield is one of three to be converted to what the council calls a "throughabout", with three lanes in both directions going through the middle for ring road through traffic. Another two lanes will be for traffic turning off the A4174 both east and west. Capacity of side roads will also be increased. The existing pedestrian crossing and access steps to the north of the junction will be removed for safety reasons, and nearby lay-bys on both sides of the ring road will be lost as they become part of the widened carriageway. The revised layout will link in with the changes on Carson Road to improve access to the Mangotsfield Sort It recycling centre.

The Siston Hill roundabout in Mangotsfield is one of three to be converted to what the council calls a "throughabout", with three lanes in both directions going through the middle for ring road through traffic. Another two lanes will be for traffic turning off the A4174 both east and west. Capacity of side roads will also be increased. The existing pedestrian crossing and access steps to the north of the junction will be removed for safety reasons, and nearby lay-bys on both sides of the ring road will be lost as they become part of the widened carriageway. The revised layout will link in with the changes on Carson Road to improve access to the Mangotsfield Sort It recycling centre.

A THREE-year project to transform five roundabouts on the Avon Ring Road has been unveiled.
The £30 million scheme would see new lanes built to take through traffic across the middle of three roundabouts – Siston Hill near Mangotsfield, Deanery Road near Warmley and Kingsfield, at Longwell Green – transforming them into what the council calls "throughabouts".
The other two – Lyde Green roundabout, near the Bristol & Bath Science Park, and the Rosary roundabout, by Emersons Green shops – would have extra lanes added.
South Gloucestershire Council has launched a public consultation on the plans, which it says are aimed at tackling congestion on the A4174 and stopping drivers using nearby residential roads as rat-runs.
But the scheme has already attracted criticism from the newly-elected Metro Mayor, Dan Norris, who said "changes might be necessary".
The council says that although the scheme, on a five-mile stretch of the road, involves widening, the intention is to encourage “necessary strategic car trips” on the A4174 because it was the most suitable for commutes in the area.
The plans are part of a "wider strategy" that also involves closing potential 'rat runs' such as Henfield Road and Coxgrove Hill near Lyde Green to through traffic.
The council claims the scheme will improve air quality by easing congestion.
More traffic lights and entry lanes will be installed, some trees removed and replaced, and land at the edges of the dual carriageway used to provide extra space for vehicles.
No dedicated bus lanes are envisaged but sensors will detect when buses are approaching to give priority, while improvements for pedestrians and cyclists are also included.
A council spokesperson told the Voice that the plans had been designed to work "with or without" the proposed new junction 18a for the M4, which could be built near Emersons Green or Pucklechurch.
The spokesperson said: "The junctions have been designed to accommodate the expected traffic from a new junction at J18a and other predicted growth across the region, and to be complementary to such a scheme."
The council said the scheme would "provide additional capacity and thus resilience along the ring road", which would make it less susceptible to being blocked by accidents.
Work on the five roundabouts would be carried out "in a phased manner to ensure that construction can be completed as quickly as possible and disruption kept to a minimum," said the spokesperson.
Responding to criticism about an apparent lack of bus lanes in the plans, the council said: "The provision of bus lanes is not required, as the ring road would enable the buses to travel without delay, using the ‘ahead’ traffic lanes provided at the junction."
The council said it had not waited until the first of its "throughabout" junctions, currently under construction at Wraxall Road near Warmley, had been completed before drawing up plans for more of the junctions, as it had a "high degree of confidence that the Wraxall Road scheme will perform as expected".
Feedback from the public consultation will be used to form a business case to be sent to the Government for approval and funding, with work expected to start in phases from next year and last until 2025.
Council cabinet member for strategic infrastructure Steve Reade said: “We want to reduce congestion and improve air quality in South Gloucestershire.
“This scheme is designed to encourage necessary strategic car trips to remain on the A4174, the most suitable road designed to accommodate longer distance car journeys, and to deter the traffic from re-routing through our local communities.”
The council says that without the changes, congestion on the A4174 and nearby roads "will worsen due to planned local growth in the area".
Mr Norris, who has strategic regional responsibility for transport, said: "I will be looking at roadworks under way to see whether changes might be necessary.
"We have to look at the strong possibility that just widening roads simply causes increased journeys by car and does not alleviate congestion."
The scheme was also criticised by South Gloucestershire Green Party, who said: "The proposals for five monstrous Mega-roundabouts will do nothing to tackle the climate emergency and will instead cause environmental damage and an increase in car dependency. Local residents have also shared with us their concerns about many years of disruption to the roads and the potential worsening of air quality, especially for people with respiratory conditions like asthma."
In Emersons Green, where work would take place on two roundabouts, town councillor Sadik al-Hassan said: "I, like many people, was surprised to hear that the roundabout needed improvement at all, but also wonder if the disruption is really worth any benefits.
"I am amazed that we have money for the roundabout upgrade but no doctors surgery in Lyde Green to reduce pressure in Emersons Green surgery. We need more healthcare, more schools and more green spaces, not necessarily bigger roads."
The consultation on the changes is open until August 16. More details can be found online at consultations.southglos.gov.uk/A4174Improvements.
Anyone not online can ask for more information by calling the council on 01454 868 000. A face-to face consultation meeting will be held on July 10 from 1pm to 5.30pm at Emersons Green Village Hall.

Includes reporting by Adam Postans,
 Local Democracy Reporting Service