August 1, 2008 Using a mathematical model, transportation engineers can design optimum traffic light timing patterns for the fewest stops and driving delays. Improving traffic flow would decrease fuel consumption. The best scenario would be for traffic to move like a train, with drivers maintaining similar speeds, and never needing to slow for a red light.
No one likes being stuck at a red light. Poor traffic light timing not only hurts your commute, it can hurt your wallet. Now, there is a way that small change in traffic lights can save you big in gas money.
With record high gas prices, consumers find ways to save fuel and save money. But gas pumps aren't the only thing sucking up your money. Out-of-sync traffic lights are costing drivers an extra five trips to the pump every year. Now, transportation engineers are working to time traffic lights better to improve traffic flow. It could help cut fuel consumption up to 10%, and save 17-billion gallons of gas a year!
"Basically try to find a timing plan that could satisfy drivers needs, try to go through the lights without being stopped every time," says Byungkyu Park, Ph.D., a transportation engineer at the University of Virginia.
The engineers, applying operations research, developed a computer simulation program to re-create a virtual road in Charlottesville, Va. The program watches traffic flow and searches for the best traffic light timing pattern that has the least amount of stops and delays for drivers. "If we believe in computer simulation models, sometime that travel times could be reduced by 20 to 30 percent," Dr. Park says.
For a thousand dollars per intersection, the U.S. could have well-timed lights, less congestion and more fuel savings. Something consumers are watching closely. It would cost the U.S. $250 million a year to change traffic lights.
Instead, billions of dollars are spent on building or widening roads -- a far more costly approach to yield similar results. Giving the green light to save money.
TRAFFIC FLOW: Scientists studying traffic's ebb and flow create complex mathematical models in order to simulate the actual patterns that emerge on roads. These models are an important part of efforts to improve the placement or timing of various items like traffic lights, additional lanes, and more. The scientists use insights developed from sources as diverse as the physics of fluid flow and human reaction time in order to build better models and glean insights from them.
THE PHYSICS OF TRAFFIC: Conventional scientific wisdom compares traffic jams to the process of freezing, where a flowing liquid turns into a solid. On a sparsely populated highway the cars are far apart and can move at whatever speed they choose while freely moving between lanes -- much like the molecules in a gas. In heavier traffic, the cars are more densely packed with less room to maneuver, so cars move at slower average speeds and traffic behaves more like a liquid. If the cars become too densely packed, their speed is reduced, and their movement restricted, to such an extent that they almost stop moving altogether and form a "solid" expanse of traffic -- "freezing" into ice.
The Human Factors and Ergonomics Society and the Institute for Operations Research and the Management Sciences contributed to the information contained in the TV portion of this report.