TRAFFIC LIGHTS

The government is facing a legal challenge from thousands of motorists after the attorney-general admitted that they had been wrongly penalised for jumping red lights. Drivers could have three penalty points scrubbed from their licences following the discovery of a legal loophole that has existed for 16 years. The problem relates to motorists who have been penalised by traffic cameras or policemen for going through red lights at more than 300 level crossings that have been created since 1990.

The crossings were signed off by the Health and Safety Executive (HSE), but government lawyers have realised that, according to current law, only the Department for Transport (DfT) and its immediate agencies, such as the Highways Agency, have the power to approve them. That means that the 306 level crossings have, technically, been erected illegally. Those drivers who have been fined and had their licences endorsed with penalty points after being caught jumping red lights at these crossings will now be able to challenge these offences.

Both Lord Goldsmith, the attorney-general, and Ken Macdonald QC, the director of public prosecutions, are understood to have been consulted over the bungle. “We have got to assume that we’re talking about thousands rather than hundreds of drivers, given the number of level crossings involved,” said a Whitehall source. However, motorists who have been prosecuted for more serious offences, such as dangerous driving, at these crossings are unlikely to have their cases quashed by the courts.

The loophole came to light as government lawyers pored over the Road Safety Bill. The government, however, is unlikely to disclose the location of these illegal rail crossings until the Road Safety Bill has received royal assent. A source said, “We will try to make it as difficult and as expensive as possible for anyone to challenge us in the courts. Even though these drivers might have been wrongly penalised due to a technicality, we would use the moral argument that they were potentially endangering lives by ignoring a red light.” (Source: Times Online, Oct/06)

Traffic lights have been installed at the A38 Abbey Hill roundabout at Little Eaton to ease congestion. The lights cost £220,000 and will work on a part-time basis during the afternoon between 3pm and 7pm. Motorists said the new configuration is dangerous, with drivers from the B6179 Alfreton Road making their own judgments about whether or not it is safe to enter the flow of traffic. Mike Taylor of Little Eaton, said, "I use the roundabout a lot and the new lights are dangerous. You take your life into your own hands if you're trying to get on the roundabout from Alfreton Road. They either need to change the timing of the lights or put lights at the Alfreton Road junction."

A spokesman for road contractor AMScott, who installed the lights, said he believed the installation of the traffic lights has improved traffic on the roundabout saying, "Instead of Alfreton Road drivers having to wait for a random gap in the traffic on the roundabout and then reacting very quickly to it, the gaps in traffic are more regular and for longer. This means they can enter the roundabout more safely then previously."

He added, "We've observed several vehicles leaving Alfreton Road in one phase of the traffic signals. Previously they would only have been able to exit one at a time as gaps appeared. The scheme was designed to reduce congestion on the major routes and we believe we're already having significant improvements. However, we'll have to wait until traffic patterns have settled to get accurate figures and we're monitoring and adjusting the signal phasing on a daily basis."

Ever felt that the traffic lights are against you? Well, perhaps they are. Lights synchronized to ease jams might be making matters worse, and rush-hour traffic might flow better if lights were set at random. Ideally, traffic lights are set so that each changes to green just as a typical vehicle approaches from the previous set of lights. But in dense traffic, queues inevitably build up behind red lights, and it may be impossible to ensure that each queue is fully cleared during a single 'green-light' period. It then becomes tricky to work out the best way of phasing the lights. Urban planners trying to deal with dense traffic currently have little more than a few empirical rules of thumb to guide their decisions, say Ding-wei Huang and Wei-neng Huang of Chung Yuan Christian University in Chung-li, Taiwan.

They need a more systematic understanding of how different modes of traffic-light synchronization affect traffic flow, the duo argue. Huang and Huang used a well-established computer model of traffic flow to simulate a long, straight section of road that cars enter and exit at a fixed traffic density. They positioned ten traffic lights at regular intervals along the road - these might, for example, be used to control the flow where the road intersects with others. They found that when traffic is light, cleverly synchronizing the lights improves traffic flow, compared with no synchronization. In fact, a good choice of delay times produced a flow similar to that when there are no lights at all. Bad timing, on the other hand, made the flow slower than if lights were set at random.

But above a certain density of traffic, typical of daytime flow in many cities, the choice of delay time stopped making any difference to flow, the pair found. In such traffic, lights turning green failed to clear the queue that had developed in front of them. Vehicles almost always had to wait at every set of lights - giving journeys that all-too-familiar stop-go pattern. In very heavy traffic, however, careful synchronization of the lights can improve matters again, the pair discovered. But here the traffic flow is much more sensitive to random fluctuations in density, which can obliterate any advantage gained by synchronization.