Driving when traffic signals are out of order requires a driver to be extra vigilant and extra courteous to other road users. This can sometimes result in a quicker trip for everyone.
This is not because traffic signals slow traffic unnecessarily. It’s because under normal driving conditions most motorists drive selfishly and selfish driving slows everyone down, according to a recent study.
Last year, researchers from Korea and the US released a report called “The Price of Anarchy in Transportation Networks” which looked at the behaviour of traffic on busy road networks.
They found that, as each driver strives to find the most efficient path through traffic to their destination, they in turn create more congestion by constantly shifting lanes and seeking out previously clear routes.
The result is that all traffic slows.
The study also examined how adding extra roads to a congested road network can sometimes increase congestion instead of easing it.
This is known as Braess’s Paradox.
Braess, a German mathematics professor, found that by adding a street to a congested four-street network, traffic across all roads in the network slowed down as drivers shifted towards the shortest known route.
Reducing available routes or removing features that cause traffic conflicts can, in some instances, force drivers to take a path which is more efficient for the entire road network.
In 1990, New York’s congested 42nd Street was closed for Earth Day. Instead of the traffic jams that were predicted, traffic flow actually improved, reported the New York Times.
Individual reaction to a street closure is also a factor. If people decide that a closure will increase congestion they may stay away, take an alternative route or take public transport.
Shifting more social responsibility towards the driver is also behind a traffic design concept known as Shared Space, where traffic lights and other traffic management devices are removed.
Drivers are then forced to observe the traffic flow and take more responsibility for their own actions.
A number of Shared Space projects have already been successfully conducted across cities and towns in northern Europe.