Travel increased more than 65 percent between 1970 and 1990, and is expected to double by 2020, the consortium says. Backers say automating traffic will allow cars to travel faster and closer together, which means three times as many cars per lane. Taking the driver mostly out of the equation also will mean safer roads, supporters say. How the car works In San Diego, the consortium showed several ways to automate a car. In all methods, the cars are steered by sensors that read the vehicle's road position 250 times per second, eight times faster than the eye can.
Radar sensors measure the distance and relative speed between each vehicle.
The sensors communicate information for the brake and throttle controls 50 times per second. Radar-reflective aluminum tape, developed by Ohio State University and made by 3M, is placed in the middle of the lane. It reflects radio waves sent by radar mounted on the car's front bumper and picked up again by the radar. Radar also is used for detecting cars and objects in the next lane. Forward-looking lasers are used for slowing down and speeding up.