Girl in traffic in Thimphu, Bhutan, a country with no traffic lights (EyesWideOpen/Getty Images)

Innovation

Polite drivers cause traffic jams, says new research

2 September 2014 | By Rod Sweet | 9 Comments

Motorists who are too polite or timid in their driving style are the cause of lengthy traffic jams where roadworks are underway, a scientist has said.

People are reluctant to use empty lanes where lane closures are approaching so they merge early, which doesn’t help traffic flow and wastes very expensive stretches of road, says Dr Guy Walker, Associate Professor in Human Factors with Heriot-Watt’s Institute for Infrastructure and Environment in the UK.

People are self-conscious, if everyone else is merging early you become extremely reluctant to do something different– Guy Walker, Heriot-Watt University

In a search for novel solutions to traffic jams, Walker has been working with the Scottish Road Research Board and traffic simulation company SIAS Transport Planners, and he has concluded that big traffic problems are caused by the small actions of individual drivers.

“No one wants to be seen by fellow drivers as the type of person who pushes in,” he said. “This behaviour, however, leads to the loss of a further lane of capacity, that’s in addition to the ones already closed because of roadworks.”

This is a waste, Walker says, because it costs about $50m (£30m) to build a mile of motorway and about £40,000 per year to maintain it, so drivers’ reluctance to be pushy means that this expensive resource is not being used.

“People are self-conscious,” Walker says. “If everyone else is merging early you become extremely reluctant to do something different, even if a big sign at the side of the road is telling you to. Behaviours like these are contagious, which is why people merge into the inside lane earlier and earlier, making congestion, anxiety and frustration worse.”

To reduce the amount of time spent queuing and in turn reduce the stress levels of drivers, Dr Walker suggests simple solutions taken from an unlikely source, the amusement industry, which has grappled with the psychology of queueing.

At theme parks, popular rides have signs estimating the wait time. If people get through the queue faster than the estimate, their emotional response is not anger at having had to wait so long, but rather happiness at having cheated the inconvenience a little.

“Research shows people who arrive at the front of a queue more quickly than expected are the happiest of all,” Walker said. “There are lots of clever ways we can help to reduce drivers’ anxiety while queueing and make waiting times seem shorter than they really are. Instead of signs saying ‘stay in lane ’what about ‘drivers ahead don’t mind you pushing in’?”

He added: “If drivers aren’t using this expensive resource because we object to pushing-in, then we have a problem. The good news is that we don’t necessarily need lots of big expensive engineering to regain the lost lane of capacity. Instead we can use small, clever and highly cost-effective solutions.”