Driving Smart
You know those people you hate to drive behind- the ones putting on makeup, gabbing on the phone, reading a map or performing other dangerous stunts while driving? Automated highways of the future would make such chores commonplace- and safe. With the flip of a few switches, tomorrow’s drivers could cruise along California freeways with their hands and feet free.
A typical Ventura Freeway trip, circa 2020 for example, could actually be a safe, pleasant experience, free of the tie- ups, stop- and- go driving and vehicles weaving between lanes. So say the proponents of an automated highway system (AHS), which would utilize magnetic sensors to keep cars in lanes and radar to keep them a safe distance apart.
Next August, Caltrans will be testing such a highway along an eight- mile stretch of Interstate 15 near San Diego. A nine- member consortium, including Caltrans, U.S. Department of Transportation, General Motors, Hughes and Lockheed Martin, is working to make AHS a reality. For four days, consortium drivers will be testing 12 cars specially fitted with computers and electronic hardware along a carpool lane of I-15.
How It Works
1. Vehicle passes through validation lane for system checks. Transponder in car emits signal that gives status information for all computer systems in car. Signal is read by sensor along road. If systems are automated and functioning, driver steers into transition lane.
2. Driver indicates destination: via in-vehicle navigation system.
3. Automated highway system takes over: guiding vehicle smoothly into traffic flow. Vehicle emits signal to other vehicles in platoon. A space is created and vehicle enters lane as same speed as other vehicles. Computer regulation of the car’s speed and path frees the driver for duration of trip.
4. When ready to exit, signal is emitted: warning driver to resume manual control; transponder in car sends signal to other cars, which create space so car can exit.
The Road
* Magnetic “nails”: An inch in diameter by 4 inches long, the nails are sunk into pavement in center of each lane, spaced every 4 feet.
* Sensors, computers and communications devices: Installed in vehicles, such automated features might be considered luxury options when purchasing a car.
* Transportation management centers: Centers in California’s 12 Caltrans districts would continue to monitor flow of traffic via roadside cameras and by loop detectors in pavement.
* Keeping Your Distance: Caltrans says vehicles in I-15 experiment will be kept about 9 and 12 feet apart. Further testing between now and August might bring that space down to about 3 feet.
Command Centers
Like the Caltrans Smart Corridor that opened on the Santa Monica Freeway last week, AHS will utilize Traffic Management Centers, but even more efficiently. Terry Quinlan, who is heading Caltrans’ role in the automated highway test program, says an automated traffic lane can theoretically handle two to three times current highway capacity, “The idea is to keep traffic flowing at a consistent rate. Overall efficiency would be increased. (Automated highways) don’t necessarily equal more cars, but more efficient use of highways.”
Technology
Cars driving on automated highways will be guided under lateral (steering) and longitudinal (speed and spacing) control:
A. Lateral control: Automatic steering keeps car in lane. Six megnetometer sensors mounted to front and rear bumpers will send date to on-board computer to analysis. Once the computer determines the car’s position in its lane, it issues commands to oar’s steering actuators. Driver may resume manual control of steering at any time.
B. Longitudinal control: Adjusts spacing in front and back of vehicles. Radar mounted in front bumper allows all cars in platoon to communicate and coordinate movement. Uses radio, small antenna similar to cellular phone, mounted in rear. Radar sensors communicate with on-board computer, which then issues commands to brake and throttle actuators.
Sources: Caltrans; National Automated Highway System Consortium. Researched by JULIE SHEER / Los Angeles Times
