Mathematicians from the University of Exeter say they have solved the mystery of traffic jams by developing a model to show how major delays occur on our roads, with no apparent cause.
Many traffic jams leave drivers baffled as they finally reach the end of a delay only to find no visible cause for their delay. Now, a team of mathematicians state they have found the answer and published their findings in the journal Proceedings of the Royal Society.
The team developed a mathematical model to show the impact of unexpected events. Their model revealed that slowing down below a critical speed when reacting to such an event, a driver would force the car behind to slow down further and the next car back to reduce its speed further still.
The result of this is that several miles back, cars would finally grind to a halt, with drivers oblivious to the reason for their delay. The model predicts that this is a very typical scenario on a busy highway (above 15 vehicles per km). The jam moves backwards through the traffic creating a so-called ‘backward travelling wave’, which drivers may encounter many miles upstream, several minutes after it was triggered.
Dr Gábor Orosz of the University of Exeter said: “As many of us prepare to travel long distances to see family and friends over Christmas, we’re likely to experience the frustration of getting stuck in a traffic jam that seems to have no cause. Our model shows that overreaction of a single driver can have enormous impact on the rest of the traffic, leading to massive delays.”
Drivers and policy-makers have not previously known why jams like this occur, though many have put it down to the sheer volume of traffic. While this clearly plays a part in this new theory, the main issue is around the smoothness of traffic flow. According to the model, heavy traffic will not automatically lead to congestion but can be smooth-flowing.
This model takes into account the time-delay in drivers’ reactions, which lead to drivers braking more heavily than would have been necessary had they identified and reacted to a problem ahead a second earlier.
Dr Orosz continued: “When you tap your brake, the traffic may come to a full stand-still several miles behind you. It really matters how hard you brake - a slight braking from a driver who has identified a problem early will allow the traffic flow to remain smooth. Heavier braking, usually caused by a driver reacting late to a problem, can affect traffic flow for many miles.”
The research team now plans to develop a model for cars equipped with new electronic devices, which could cut down on over-braking as a result of slow reactions.
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Lexus Hoverboard Gets Off The Ground
- Vegan Diets Works Better For Weight Loss Than Vegetarian Or Atkins
- Asteroid Day Today, 30th June - Let's Find These Rocks And Deflect Them
- High-Fat Diet And Natural Hormone May Alleviate Mitochondrial Disease
- Qualitative Research: Lessons From Rashomon
- Antibiotic Incentives: Marketing Vs. Education
- "Want to add about cometary meteorites, that the lack of them is especially funny since the regular..."
- "This is in defiance of everything we know about cellular respiration. The notion that an energy..."
- "The above was not proofed and as for grammar well it was the working notes. Sorry..."
- "During the 1970s in California the plumbers and associated trade unions attempted to get PVC outlaw..."
- "I read somewhere that a study showed that a telescope at Venus' orbit would not find any asteroids..."
- Phase IIb Pivotal Clinical Study of P2B001 for the Treatment of Early Stage Parkinson's Disease
- Women's faces get redder at ovulation, but human eyes can't pick up on it
- Friction reduction breakthrough is not snake oil
- Is abortion in America about to get restricted?
- South Africans used milk-based paint 49,000 years ago