The world's largest-ever test of connected vehicle technology got underway in Ann Arbor this week.
Experts predict that our cars will one day routinely "talk" to one another with wireless communication devices -- preventing huge numbers of traffic accidents.
Already, ordinary motorists have experienced driving with the devices on closed courses. One study was held last year at the Michigan International Speedway.
Now, in the next step, the technology is being tested under real-world conditions. By October, the University of Michigan Transportation Research Institute (UMTRI for short) plans to install some version of wireless car-to-car communication devices in nearly 3,000 people's cars, as well as on some city and school busses.
Traffic signal-to-car communication devices will be installed at numerous intersections; others will be mounted near potentially dangerous sections of roadway.
See a video of how the technology works:
For a year, the motorists will travel their usual ways, occasionally crossing paths.
UMTRI will collect the data, which will eventually help researchers determine how well the technology works in real life. Researchers may be able to prove that a handful of accidents were averted.
But the real potential for the technology is when it is adopted on a wide scale, in millions of vehicles.
UMTRI Director Peter Sweatman thinks the potential to save lives is huge.
"Motor vehicle injuries and fatalities are the number one public health problem in this country -- I don't think people realize that," Sweatman says, standing in a big garage bay where technicians are installing the devices in study participants' cars. "Between the ages of 1 and 35 - that's the no. 1 cause of death!"
Sweatman says cars are much safer than they used to be, thanks to better design, seat belts, air bags and electronic stability control.
Yet, because people are driving more than in decades past, the reduction in traffic deaths is hardly ticking down at all from year to year. "That's unacceptable," he says.
Most of the car accidents that kill people are due to human error - even when you take away alcohol-related accidents.
It's hoped that by giving cars more ability to communicate with each other, and with their human drivers, accidents will plummet.
Melissa Donia works for a company that has contracted with the U.S. Department of Transportation for this study. She takes me on a test drive to show me one scenario where connected vehicles could avert an accident.
She lines up her car behind two others on a closed road next to the UMTRI building on the North Campus of the University of Michigan, and gives the signal via walkie-talkie to the drivers ahead to go.
"Imagine you're driving along doing a moderate speed 35-40 miles an hour and there are two or three or four cars ahead of you," she narrates, as she picks up speed.
At some point, the driver in the front is going to randomly hit the brakes - but Donia doesn't know when.
"Not only is our view of that sudden braking impeded by the traffic between us," she says, "possibly the traffic between us doesn't realize that that car has slammed on its brakes as well."
Without car-to-car communication devices, such a situation could well result in a multiple-car pileup. But these cars have been equipped not only with wireless receivers and transmitters, but audio, visual and tactile warning systems.
Donia's seat will vibrate when there's a danger ahead - it will even vibrate on the left side only if the danger is on the left, and on the right side, if the danger is on the right.
So when the front driver brakes suddenly, Donia receives a heads-up. "Hard braking ahead," says the warning.
It gives her several extra seconds to respond, and she comes to a stop at a safe distance from the car in front.
Each transmitter sends a signal about its longitude and latitude, direction, and speed, ten times per second.
"So pretty high frequency," says Jim Sayer, the study's director at UMTRI. "You need that really high transmission rate, because crashes can occur really quickly - in a second or a half a second."
The technology isn't without its risks. Many people are already distracted when they drive. David Champion of Consumer Reports says the potential benefits of the technology are very large. But he's worried that people will allow themselves to become even more distracted, if they assume their car can watch the road for them.
There's also a philosophical objection -- because now it's the car telling the driver what to do.
Eddie Alterman is Editor in Chief of Car and Driver Magazine. He says throughout the 20th century, the car represented freedom.
He says that ideal is now being challenged by the high-speed data transmission made possible in the 21st century. He figures it poses a worrisome threat to personal freedom.
"Isn't that (connected vehicle technology) kind of un-American? I mean, what would Teddy Roosevelt say about this?" he asks, only half-joking. "What happened to the rugged individualist?"
Alterman says this is all too Big Brother for his taste. Connected vehicles could allow the government and insurance companies to track everywhere motorists go.
But his fears weren't widely shared among people who tried out connected cars on closed courses in earlier tests, according to Melissa Donia.
And the technology also offers the potential to save not just lives - but frustration.
Jim Sayer of UMTRI says traffic signals that communicate with cars could create so-called "green waves," of traffic, allowing someone to breeze through a city with very few waits at a red light. That could save motorists untold gallons of gasoline and hours of sitting in traffic in their lifetimes.
It's worth noting this future is at least a decade away. Fully autonomous vehicles, that do most of the driving for us, are even further down the road.
And even when that future does arrive, it's entirely possible nothing will ever replace the hands-down most effective life-saving piece of technology invented for the automobile -- the seat belt.