This double speed camera on 16th street NW can tag cars from both the southbound and northbound lanes. (Michael S. Williamson/The Washington Post)

With a politically fractured Congress and a polarized nation, the idea at first blush has universal appeal: save almost 10,000 American lives each year and virtually end the need to import foreign oil.

Sounds like a classic win-win, but the idea is such a loser that nobody talks about it.

End speeding.

The best proof yet that automated speed cameras curtail the urge to speed — considered a virtual birthright by many drivers — will be presented Tuesday at a convention in Nashville. The detailed research by the Insurance Institute for Highway Safety focuses on Montgomery County, Md., which began using speed cameras in 2007.

The report says the county’s cameras have reduced by 59 percent the urge to drive more than 10 mph above the speed limit, when compared with a county in Virginia — Fairfax County — that doesn’t use speed cameras. It concludes that if all communities nationwide used speed cameras, more than 21,000 deaths or serious injuries could be prevented.

“Speed is a factor in over­ ­50 percent of the fatal crash reports,” said Deborah A.P. Hersman, president of the National Safety Council and former chair of the National Transportation Safety board. “It may not be the only factor. It could be alcohol and speeding, but technology gives us the opportunity to get a lot more bang for our buck when it comes to law enforcement.”

For generations, speeders were caught only when police chased them down, and the odds of that happening were so slender that almost everyone broke the law.

But now, law enforcement has tools that could make people slow down, and within a matter of years there will be systems that could virtually end speeding, if there is public and political will to allow their use. So far, the report to be presented Tuesday at a convention of the Governors Highway Safety Association, says only 138 jurisdictions in the United States have embraced automated speed cameras.

It has already happened in France, where a “war against road violence” has reduced overall traffic fatalities by 10 percent. Western Australia is waging an aggressive campaign with automated speed cameras.

In the United States those cameras churn out speeding tickets by the thousands, and there has been a backlash. Many critics of the cameras contend jurisdictions install them for their revenue-generating ability rather than to promote safety. Installing them everywhere, including interstates, has been a political non-starter.

“I think the public reaction would be uproar,” said Dwight Hennessy, a psychology professor at the State University of New York College at Buffalo. “Compared to some other cultures, we have a more risk-taking approach to driving. We over-glorify certain unsafe behaviors like speeding. The way people rationalize this is that the speed limit is arbitrary. Who is it that’s decided 60 miles an hour is safe on this stretch of highway and 61 isn’t?”

Twelve state legislatures have voted to prohibit the use of speed cameras. More than 40 percent of people in the region polled by The Washington Post two years ago said they oppose their use, and the opposition was stronger in the two jurisdictions — the District and Maryland — where speed cameras are used. They were regarded more favorably in Virginia, where there are no speed camera programs.

“This study connects the dots to show that speed cameras save lives,” said Adrian Lund, president of the insurance institute, which can draw on a vast data bank of insurance claims in addition to accident reports. “Speed cameras get drivers to ease off the accelerator, and crashes are less likely to be deadly at lower speeds.”

Lower speeds also mean less fuel consumption. Consumer Reports said a Toyota Camry got ­40 miles per gallon at 55 mph, five gallons less at 60 mph and an additional five-gallon drop at­75 mph.

By the end of last year, Montgomery County was using 56 fixed speed cameras, 30 portable cameras and six mobile speed vans. The mobile cameras are moved frequently along key corridors to keep drivers guessing.

“Speed camera corridors force drivers to watch their speed for the length of the road, instead of slamming on the brakes at a specific location and then speeding up again,” said Anne McCartt, an institute vice president who co-authored the report.

Her study found that crashes resulting in fatal or serious injuries on speed camera roads had declined by 49 percent in Montgomery by 2013.

Capt. Tom Didone of the Montgomery police department’s traffic division said the report validates the effectiveness of the county’s speed-enforcement program.

“Speed cameras can effectively change behavior and reduce the likelihood of collisions,” Didone said.

In addition to calculating speed reductions, the institute surveyed Montgomery drivers and found that almost all of them were aware of the cameras. Seventy-six percent said cameras had caused them to reduce their speed, and 59 percent said they had received at least one citation generated by a speed camera.

As for safety, the history of the U.S. driver has made one thing clear: People who ignore all the warnings and signs will respond to the prospect of being caught. Think about the crackdown that put drunk drivers in handcuffs and the “Click It or Ticket” campaign that fined people for failure to buckle up.

In known speed camera locations, alert drivers slow down and the rest of the cars have little choice but to slow with them.

“This study demonstrates that automated enforcement can be an effective deterrent to speeding,” said Jonathan Adkins, executive director of the Governors Highway Safety Association. “The Montgomery County program is a model for other communities looking to address this often overlooked, yet pervasive dangerous driving behavior.”