Curfew draws near for smart traffic

When I was learning to drive, there was only one traffic light in town.I don't know whether there was a system for triggering the light to change,but if there was, it didn't work well. You could wait a long time for the light toturn green.Late at night, particularly if you were on Main Streetand needed to get home quickly, you could move intothe intersection enough to see up and down BroadStreet. If the coast was clear, you could run the red light.Today, there are three traffic lights in Luray, Va., allwith sensors that monitor the flow of vehicles and managethe switching from red to green and backagain.Most drivers, including 17-year-olds tryingnot to miss their curfews ? teenagers stillhave curfews, don't they? ? probably don'tthink about the software and informationtechnology that drives the logic of a trafficlight system.As James Schultz explains in this issue'scover story, the next generation of traffic systemsis moving well beyond just controlling intersections.The new systems that are coming online control tasks such as promptingdrivers to pay to use certain lanes or giving them more information on trafficcongestion to make better choices.It isn't science fiction anymore to think about cars trading information withone another on their relative speed and distance and then adjusting their movementaccordingly.The goals are multifaceted: Easing congestion, making the roads safer andcutting energy consumption are chief among them.Much lower on the list, I'm sure, is helpingteenagers make their curfew.