That movie staple, the tire-squealer of cops chasing a getaway car, is fun to watch, but deadly. Some 300 people die in the 30,000 car chases a year. Another one died a few days ago in New York, an 83-year-old nun, Sister Mary Celine Graham. She was hurled 15 feet into the northbound lane by a minivan fleeing the police after three men attempted a gunpoint robbery.

Everyone is obsessed with technology for entertainment and yakking. I thought of how technology can save lives. OnStar, a wholly owned subsidiary of General Motors—yes, the General Motors we all own—has now thoroughly developed its prototype technology that can reduce the lethality of car chases, if not end them altogether.

A driver who has a GM car or truck quipped with OnStar’s Stolen Vehicle Slowdown system can get a remote signal sent to his car that interacts with the powertrain gradually to reduce engine power. That means the cops can catch up safely. The signal doesn’t cancel out the power steering or brakes, so the driver can still steer and stop his faltering vehicle.

The hijacker fleeing at speed in the Chevrolet Tahoe he’d stolen from two men he robbed at gunpoint at Visalia, California, thought he’d gotten clean away. OnStar’s advanced global-positioning technology pinpointed his exact location. Cops were able then to get the speeding Tahoe in their line of sight, the signal went to the powertrain, and the miscreant was stunned to find that stepping on the gas had no effect. When the Tahoe came to a dead stop, he jumped out and was swiftly caught—just 16 minutes after OnStar was activated.

Mississippi State Senator Terry Burton hadn’t a clue what had happened to his Impala. OnStar located the vehicle, going like the wind; then cops using SVS slowed it and recovered it. Burton remarked, “I am pleased my Impala returned to me without damage, but even more grateful that no one was injured during the commission of this crime.”

The newest generation of the hardware, Remote Ignition Block, ensures that a thief can’t hide the car and reclaim it later. It just won’t start again.

SVS is catching on from a slow start. GM is getting about 500 stolen car reports a month. Stolen Vehicle Slowdown technology was launched on select OnStar-equipped GM vehicles and is now standard across the portfolio as part of the latest generation of hardware.

Cops were able to get the speeding Tahoe in their line of sight, the signal went to the powertrain, and the miscreant was stunned to find that stepping on the gas had no effect.

There’s good news, too, from OnStar Mobile to everyone eyeing the Chevrolet Volt electric car, due to go into production this November. The first smart phone application for an electric car will now allow Volt owners 24/7 connection and control of the Volt’s functions through the Motorola Droid, Apple iPhone, and BlackBerry Storm. Owners will be able to start the Volt remotely, taking power from the grid to precondition the interior temperature and preserve the battery for driving without gasoline. They’ll also be able, manually, to set a grid-friendly charge mode to take power at off-peak times when rates are low.

The Volt is designed to drive up to 40 miles on electricity without using any gas or producing tail emissions; that’s long enough for 75 percent of American commutes. When the Volt’s lithium-ion battery is depleted, an engine generator comes on line to extend the driving range to some 300 miles before refueling or stopping to recharge the battery.

Maybe our investment in GM will bear fruit in the end.

Harold Evans, author of two histories of America, just published his memoir, My Paper Chase. Editor at large of The Week, he was editor of The Sunday Times from 1967-81 and The Times from 1981-82, founding editor of Condé Nast Traveler, and president of Random House Trade Group from 1990-97.