Ready to Rumble

Two auto makers in Europe have started TV advertising of a virtual rumble-strip system that almost certainly will save lives — even if it may be hard to sell.

The system will be introduced in a U.S. passenger vehicle next year.

The commercial by France's PSA Peugeot Citroen explains how infrared sensors mounted under the car can detect when the front tires drift over the white lines at the right or left side. DaimlerChrysler AG shows a nearly wordless trucker's-eye view of a drab stretch of desert highway in which the driver blinks, closes his eyes and swerves into the wrong lane before jerking awake and recovering.

Iteris Inc., a California company specializing in imaging software for intelligent highway systems, developed a system for trucks that Mercedes-Benz introduced on its Actros in 2000. It has migrated to trucks sold by Freightliner Corp., International Truck and Engine Corp. and MAN AG.

Next year, Iteris — a former Rockwell division now owned by Odetics Inc. — and Valeo SA will bring the system to the automotive market for the first time, for an unspecified North American auto maker.

The image-based systems for trucks and cars are similar. A camera watches the road ahead to the right and left of the car's path, and software identifies the repetitive pattern of the road markings in the picture.

If the car moves out of its lane, the driver is alerted by either the sound of a rumble strip or by a vibration in the seat or steering wheel, which is called a haptic warning. The reaction to correct the course is instinctive.

Truck systems now on the road are sound-based, says Joachim Mathes, Valeo's research and development director for switches and detection, but a haptic system that warns the driver only is more discrete and likely to be preferred by light-vehicle customers. A sound warning would wake up sleeping passengers as well as the driver and could lead to heated criticism of the driving. There is little difference in cost, Mathes says, even though the seat-based haptic system requires two small electric motors.

To avoid what would be false alerts in urban conditions, the system only activates at a highway speed chosen by the driver. In a demonstration vehicle in France, Valeo tuned the system to operate above 50 mph (80 km/h), while the truck system turns on at 35 mph (56 km/h). The rumble strips aren't activated if a lane change is signaled with the turn indicator.

“Iteris has 30 million miles (48 million km) of experience with reading road markings, and we bring our knowledge of the OEMs and electronic integration in cars,” Mathes says.

The car-based system is built into the back of the rear-view mirror and looks ahead 98 ft.-131 ft. (30-40 m), while truck systems are mounted much higher and need look ahead only 16 ft. (5 m) or so. Because the car-based system sees horizon and sky, the software had to be adjusted to filter out problems from that longer view.

Waking up sleeping drivers should save lives. In the U.S., some 44% of fatal accidents are related to unintended lane departures, according to the U.S. Dept. of Transportation. In 2001, such driving killed 18,762 people in the U. S.

Professional truck drivers are pleased with the technology, says Martin Haub, Valeo's director of technology. It alerts them to trouble and reinforces good habits such as signaling lane changes.

According to Iteris, a wrecked rig is a $1 million loss, which makes it easy for truck-fleet owners to justify the cost of the system.

For passenger vehicles, sales could be difficult. Buying a virtual rumble strip is tantamount to admitting you are an unsafe driver. In customer clinics, says Mathes, drivers tend to be less interested in lane-departure warnings than in another system Valeo is developing: radar detection for cars in the blind spot.

“The perception is that blind-spot detection is much more important,” Mathes says. Only after explanations of accident data and test-driving vehicles with virtual rumble strips do customers start to change their perception.

Peugeot is using a different technology for its lane detection, also expected to reach production in 2004. Light sensors look at the ground ahead of the tires for the higher reflectivity of the road markings. These signals also will be processed to limit false alerts.

While light-sensor systems are less expensive than a camera-based system today, they may not remain so. Valeo counts on virtual rumble strips to bring the camera system inside the car and higher volumes to bring down cost.