When General Motors Corp. rolls out its eighth-generation OnStar vehicle communications technology for ’09, the system’s improved integration with onboard powertrain computers will translate into a big advantage for U.S. law enforcement officials.

Dubbed Stolen Vehicle Slowdown (SVS) and billed as the latest addition to OnStar’s vehicle recovery capabilities, the prototype technology allows vehicles to be remotely slowed to a crawl in the event of a high-speed chase with police.

The enhancement is aimed at reducing casualties resulting from aggressive police pursuits in congested areas.

"From its inception, the motivation behind OnStar has been the safety and security of our subscribers and others on the road," says OnStar President Chet Huber. "The Stolen Vehicle Slowdown service will allow our subscribers added peace of mind by possibly preventing their vehicle from being used as an instrument of harm if it happens to be stolen."

Citing statistics from the National Highway Traffic Safety Admin., GM says about 30,000 police chases occur every year, with approximately 300 deaths resulting from those pursuits.

SVS is an enhancement of OnStar’s global positioning satellite-based Stolen Vehicle Location Assistance technology, which has been offered to subscribers since 1996.

As with existing versions of OnStar, subscribers reporting their vehicle stolen to police will be able have OnStar operators pinpoint the exact location of the vehicle and forward the information to police. Once police have identified the target vehicle, they then can issue an SVS request for the vehicle to be immobilized.

Safeguards, such as remote flashing of the vehicle’s lights or a prerecorded alert played through the vehicle’s speakers, may be implemented to verify the target vehicle and command the assailant to stop running, Walt Dorfstatter, OnStar vice president-engineering, says, noting GM and law-enforcement authorities still are determining what specific protocols should be implemented in production versions of SVS.

When SVS is activated, the new OnStar control module and updated software programming connect with the vehicle’s powertrain controller and electronic throttle to dial back power to minimum levels. Only minor updates to the vehicle’s powertrain electronics were needed to implement the system, Dorfstatter says.

The vehicle’s steering and brakes remain operable for control, he adds, but the engine essentially is idled, allowing the vehicle to "coast down" to a stop.

GM expects to outfit nearly 1.7 million ’09 vehicles with SVS, with Chevrolet making up more than 60% of the installations.

"Chevrolet aims to provide customers with more than they expect, and services like Stolen Vehicle Slowdown continue to add even more value to Chevy cars and trucks," says Ed Peper, general manager-Chevrolet. "Stolen Vehicle Slowdown will not only benefit GM and Chevy customers, but virtually everyone on the road."

SVS will be offered on eligible ’09 GM vehicles sold in the U.S. and Canada and will be included in the free 1-year OnStar subscription offered on most models.

Customers may opt out of the SVS service at any time without affecting their OnStar contract, but the auto maker says its internal research shows about 95% of current OnStar subscribers likely will want SVS on their vehicles.