SAN FRANCISCO -- BMWs that tell each other of slick roads. A Mercedes Benz that warns its driver in advance that he is about to run a red light. Nissans that sound a buzzer when the car veers out of a highway lane without signaling, And a prototype Toyota that braces for a crash before it happens.

All of this is on display this week at SBC Park along with General Motors cars that prevent rear-end crashes when cars tailgate because they sense and talk to each other.

University of California, Berkeley engineers have an experiment that tells drivers in advance that they will not accomplish a left turn without getting creamed by an oncoming car.

If one car could integrate all these technologies at the 12th World Congress on Intelligent Transport Systems, it would take a complete idiot to crash it.

Automakers from three continents are teaming up in unprecedented ways to allow their cars to talk to each other over the same language, or broadcast frequency.

The big promise comes from wireless. It allows car-to-car and car- to-roadside communications. So when one GM car gets too close to the other, the car in front flashes its lights and the one in rear signals the driver.

Likewise, BMW showed off its slick-road warning cars. The first car skids over wet plastic sheets on Parking Lot B at SBC Park. An array of sensors in the steering wheel, brakes, axles and accelerator tells the sliding car how to auto-correct to drive out smoothly without fishtailing.

Instantaneously, the car tells another behind it of the slippery conditions, and a hazard alert appears in a dashboard display screen in the second car.

"These cars have more computing power than the space shuttle," BMW spokesman William Scully said.

The Toyotas see objects in the road, using radar beams emitted from a device under the hood. Calculating the stopping distance based on the car's speed, they automatically sound an alarm 11/2 seconds before an inevitable collision. At the same time, the seatbelts cinch, and the nose of the car dips.

Passengers can feel in their hips the pulling force as the car hugs the road, but not the whiplash effect of a common emergency stop.

The system would not work for deer or pedestrians because radar shoots through soft, fleshy things.

Nissan boasts the only cars on the market today with collision- avoidance technology. The Infinitis released in late 2004 have forward-looking cameras mounted above the rear-view mirror. They record highway lane markings, and if a driver veers beyond them without signaling, the car alerts the driver with a beep. Nissan has tested prototypes that also jiggle the seat or automatically, but gently, apply the brake to bring the car straight.

"It is very subtle," said Alex Cardinali, Nissan governmental affairs engineer.

Daimler-Chrysler's red-light system works much the same as the others. It gets a traffic signal from a radio transmission, sent by an antenna above the traffic light. Every 100 milliseconds a new beam is transmitted and the car recalculates its stopping distance. If it seems like a driver is about to run the light, the car rings an alarm. At 40 mph, the demonstration car Tuesday stopped within a foot of the line.

An intersection wired with radio transmitters is being tested at Page Mill Road and El Camino Real in Palo Alto as part of a national experiment.

Berkeley researcher Christopher Nowakowski sees the potential to take these safety features to the next level. His team has tested a system that embeds sensors in the street to warn cars of oncoming traffic when they turn left.

After experimenting with drivers' eye motions and reaction times, researchers picked three seconds as the time to flash an electronic no-left-turn sign, based on time-distance calculations that show the two cars would collide. Two seconds before turning, most drivers have already started to slow down.

The technologies on display this week would allow the same information to be beamed into cars. Japanese automakers are developing systems that add to Berkeley's sensor data, which tell of traffic on side streets. The Japanese cars can tell each other they are in blind side streets.

Contact Sean Holstege at

sholstege@angnewspapers.com.