Imagine driving up to a busy intersection that knows you're coming - one where the signal stays green a little bit longer to make sure your car gets through safely. Thanks to new technology, intelligent traffic lights are now a reality and they're helping to make traffic congestion a distant memory.

According to the U.S. Department of Transportation, all 50 states now have intelligent transportation systems up and running or in the works. Why? Because the systems have proven to reduce traffic congestion considerably. For instance, studies for one such system called Scoot have been found to reduce peak period travel time by about 25 percent.

Scoot automatically uses sensors to detect traffic flow, and changes the traffic signals throughout the city accordingly. Engineers at a Traffic Management Center also complement the Scoot system by monitoring the city's streets via closed circuit video cameras. If they know an event is letting out at an arena, engineers can keep certain traffic signals green for longer amounts of time to accommodate the rush. Engineers can also deliver information to motorists electronically via digital signs on the road.

The system shows that building roads isn't the only way to increase traffic flow. By making traffic signals work with - and not against - drivers, traffic flow can improve considerably.