We are restricting vehicle movements at the Hambrook traffic lights from Sunday 11 August to help improve air quality.

Following detailed modelling of the impact of different options, an Experimental Traffic Order (ETO) is being put in to operation which will limit the number of vehicle movements at the Hambrook traffic lights on the A4174 ring road. These restrictions will allow east and westbound traffic on the ring road to flow more efficiently, help reduce queues at the traffic lights and improve air quality.

The restrictions follow a government direction to improve air quality on this part of the A4174 ring road. We were required to assess if there were any actions that could be taken to reduce the high nitrogen dioxide levels on this section of the ring road to meet the legal limits in the shortest time possible for all road users.

Improving traffic flow through the Hambrook junction will smooth traffic flow along the ring road, reducing the nitrogen dioxide emitted by vehicles held stationary by the tidal flow of traffic at the junction. People driving along the ring road in particular are exposed to these higher levels of nitrogen dioxide. By reducing the number of vehicles that are spending time stationary at the traffic lights, we aim to reduce nitrogen dioxide emissions and therefore improve air quality.

We have increased the level of our nitrogen dioxide monitoring to check what effect the scheme makes to air quality at the roadside.

The changes to vehicle movements at the Hambrook lights will be implemented on 10 and 11 August and whilst the majority of the work will take place overnight, we anticipate that there will be some disruption in the area that weekend including lane closures and temporary traffic lights. New directional signs will be put in place on Friday followed by the physical barriers and new road markings on Saturday and Sunday. The sequence of the traffic lights will be altered from the Sunday afternoon.

The changes will restrict a number of traffic movements and will involve:

* removing the westbound bus lane through the junction to the M32 traffic signals

* removing the right turn movement onto the B4058 Bristol Road from the westbound carriageway of the A4174 ring road

* removing the straight on movement for the B4058 Bristol Road northbound from Frenchay

* removing the right turn movement from the B4058 Bristol Road from Frenchay onto the A4174.

There are no changes to the direction of travel southbound on the B4058 from Winterbourne and both pedestrians and cyclists will still be able to cross using the existing facilities.

Cabinet Member for Transport Cllr Steve Reade said: “These changes follow the government’s Joint Air Quality Unit (JAQU) direction, which we are obliged to comply with, to improve air quality on this part of the A4174 ring road in the shortest time possible for all road users.

“Our traffic modelling has shown that the changes will allow east and westbound traffic on the ring road to flow more efficiently and help reduce queues. Improving traffic flow along the ring road will deliver benefits to all road users travelling along the ring road including metrobus and bus services using this route.

“It is important to note that this is an experimental order that can be amended through time, so if we see a particular type of road user is negatively affected then the order can be adjusted. We will be working with First bus during the implementation of the scheme to regularly review the impact, and the changes can be amended to reflect any issues identified.

“I have also asked that the road markings around the roundabout be refreshed so that road users will follow the correct lane for their direction of travel, so reducing inadvertent delays.”

The Experimental Traffic Order has deliberately been used as it allows us to gather evidence of the impact of the changes, and to amend them if necessary, before any changes are potentially made permanent. An ETO is a trial which can be in place for a duration of up to 18 months, during which time consideration is given to making the order permanent. ETOs are subject to a statutory process which allows people to comment formally and provide feedback. The consultation will open when the restrictions at Hambrook come in to effect. Visit our consultation website at https://consultations.southglos.gov.uk/consult.ti/PT.6296_Hambrook_E.T.O/consultationHome

We understand that these changes will make some journeys slightly longer as drivers will be required to drive around the M32 roundabout in order to access the B4058 northbound and or the ring road from Frenchay and we apologise for any inconvenience caused.

More information is available at https://www.southglos.gov.uk/hambrookchanges