More than 30,000 people a year still die on American roads, and while that toll has been steadily declining for a decade, it still represents a massive, unending tragedy. Around the world, those figures are climbing, as more people spend more time behind the wheel. Nothing drives advocates of tech such as driverless cars like the potential for sharply reducing the cost in human lives of driving.

Today came a piece of good news in that fight: We are closer than we thought to cars that could prevent all their drivers from dying in a wreck. The bad news? There's still decades of work ahead.

The Insurance Institute for Highway Safety, the research arm of the nation's auto insurance companies, studied driver deaths between 2009 and 2012 for mass-market vehicles. (It did not examine passenger deaths due to unreliable data.) Overall, it found that new models with newer technology, especially stability control, had cut the overall death rate in vehicles by a third in the three years since it had last run the numbers. Had vehicle tech been frozen at 1985 levels, the IIHS estimates by 2012 an additional 7,700 people would have died in crashes.

Vehicle Deaths per million registered vehicle years Multi-vehicle crashes Single-vehicle crashes Rollovers Audi A4 4WD 0 0 0 0 Honda Odyssey 0 0 0 0 Kia Sorento 2WD 0 0 0 0 Lexus RX 350 4WD 0 0 0 0 Mercedes-Benz GL-Class 4WD 0 0 0 0 Subaru Legacy 4WD 0 0 0 0 Toyota Highlander hybrid 4WD 0 0 0 0 Toyota Sequoia 4WD 0 0 0 0 Volvo XC90 4WD 0 0 0 0 Honda Pilot 4WD 2 0 2 0 Mercedes-Benz M-Class 4WD 3 3 0 0 Ford Crown Victoria 4 4 0 0 GMC Yukon 4WD 4 0 4 0 Acura TL 2WD 5 5 0 0 Chevrolet Equinox 2WD 5 3 2 0 Chevrolet Equinox 4WD 5 5 0 0 Ford Expedition 4WD 5 5 0 0 Ford Flex 2WD 5 0 5 0 Mazda CX-9 4WD 5 0 5 5

The IIHS calculates its death rate per years registered of a particular model; the industry average is 28 deaths per one million registered years for 2011 models in 2012; in 2008, the rate was 48. When it dug deeper, the IIHS found nine 2011 models that had no recorded deaths of drivers — the first time the group had found any such vehicles. Six of them were SUVs; overall, SUVs had the lowest death rates of any vehicle type, mostly due to the mandate of electronic stability controls and the physics of larger vehicles offering more protection from the forces of a crash than smaller ones. (Compared to 2004 models, SUVs from the 2011 model-year on have a rollover rate that's 75 percent less.)

Story continues

But the IIHS also gave out a warning that the gap betwen the best and the worst cars at preventing fatal crashes had widened. The rates in the IIHS study are corrected for demographics (young drivers who typically buy smaller vehicles tend to crash more frequently) but even after that adjustment, small cars dominate the most lethal list:

Vehicle Deaths per million registered vehicle years Multi-vehicle crashes Single-vehicle crashes Rollovers Kia Rio 149 96 54 15 Nissan Versa sedan 130 44 87 51 Hyundai Accent 120 65 53 16 Chevrolet Aveo 99 65 31 10 Hyundai Accent 86 43 48 20 Chevrolet Camaro coupe 80 19 60 25 Chevrolet Silverado 1500 Crew 4WD 79 40 36 17 Honda Civic 76 46 29 10 Nissan Versa hatchback 71 37 33 20 Ford Focus 70 55 13 5 Nissan Cube 66 38 29 6 Chevrolet HHR 61 34 25 9 Chevrolet Suburban 1500 2WD 60 31 28 9 Chevrolet Aveo 58 58 0 0 Mercury Grand Marquis 57 33 25 0 Jeep Patriot 2WD 57 44 9 3 Mazda 6 54 34 17 3 Dodge Nitro 2WD 51 7 50 40 Honda Civic 49 28 21 8

"The complete elimination of traffic deaths is still many decades away, and, along with vehicle improvements, getting there will require changes in road design and public policy that can help protect all road users," said David Zuby, IIHS executive vice president and chief research officer. "Still, the rise in the number of vehicles with zero driver deaths shows what's possible."

The newest vehicles have gone well beyond stability control to include tricks like automatic emergency braking and radar-based cruise control to slow down the vehicle automatically in traffic. The safety benefits of those technologies have not yet been fully measured, but their real benefit may not become visible until they're available outside luxury models — especially the small cars that still pose the greatest risk.