Traffic flows improve and pedestrian waiting times fall when traffic lights are switched off, suggests pilot project

Early results from an experiment that has seen traffic lights switched off at a Bristol intersection indicate that traffic flows through the junction have improved, reports RUDI partner website Transport Xtra.

The lights, at the Cabstand junction in Portishead, have been turned off in a month-long trial to see if the removal of formal traffic control eases congestion at the intersection, which has been the scene of protests from residents and motorists since the installation of the £800,000 signalling system in 2004. Community antipathy to the lights manifested itself in a 5,000 signature petition, two marches attended by in excess of 2,000 people, and the election of a local councillor on a pledge to remove the lights.

According to Keith Firth, director of traffic engineering at consultant Colin Buchanan, the consultant charged with monitoring the project, results so far are very positive. “The initial survey results show that more vehicles are going through the junction and that the queues and delays have disappeared,” he said. “Traffic queues have reduced from an average of 15-20 passenger car units (pcu) on all approaches to 3-4pcu, with delays reduced from over two minutes to less than 20 seconds per pcu.”

Firth said that pedestrian waiting times have also significantly reduced from up to two minutes to less than 20 seconds, though he acknowledged that there had also been a loss of pedestrian amenity and that any permanent solution would need to remedy this.

The staggered T junction is controlled by MOVA and carries around 1,700 vehicles per hour and around 200 pedestrian crossing movements per hour during the weekday peak.

In addition to the lights being turned off, the junction is now subject to a temporary 20mph speed limit and signage advising vehicles to give priority to pedestrians.

Councillor Elfan Ap Rees, executive member for highways at local highway authority North Somerset Council, said: 'This is a controversial junction and the trial will very much rely on motorists and pedestrians using commonsense to share the area. However, the trial will be abandoned and the signalling reinstated in the event of any collision or if at any time officers or members consider the safety risks to be unacceptable.'

The council plans a detailed analysis of the trial. A decision to permanently remove of the lights is likely to be accompanied by additional measures such as speed tables or zebra crossings to ensure pedestrian safety, says the council.