Oct. 11 2016

Buckle Up: Here Come Self-Driving Vehicles!

Driver-assist technologies have the potential to make motoring a lot safer, say Mailman School researchers

For nearly a month, Uber has offered Pittsburgh residents the chance to catch a ride in a self-driving vehicle. The high-tech taxis are among a variety of semi-autonomous vehicles already on the road. Of course, the technology isn’t perfect: one of the Pittsburgh Ubers was recently caught on video going the wrong way down a one-way street. More seriously, earlier this year, the driver of a Telsa S was killed in a crash while his car was in autopilot mode.

While any fatality is regrettable, Joyce Pressley, an automotive safety researcher and associate professor of Epidemiology, believes driver-assisted technologies have enormous potential to save lives. In fact, she says, there is early evidence that such technology has improved safety. 

Visions of driverless motoring go back decades. At the 1939 World’s Fair, General Motors delighted visitors with a diorama of a highway system with cars directed by electromagnetic currents embedded in the roadway. While there are few truly autonomous cars on the road today, many vehicles already offer aspects of the self-driving technology. Collision avoidance systems, which can take control of steering and braking, have been shown by the Insurance Institute for Highway Safety to be associated with reductions in property loss.

Tesla Model S interiorThe Tesla Model S takes collision avoidance a step further, allowing drivers to cede control of the vehicle during routine highway driving. In the incident earlier this year, the driver was rumored to have been watching a movie when his car crashed sidelong into a tractor-trailer invisible to the vehicle’s sensors, possibly due to poor lighting conditions. If the driver had been looking, he might have stopped the vehicle in time. (Since the crash, Tesla updated the car’s software to warn drivers to keep their hands on the wheel; after two warnings, the car disables autopilot.)

To call these cars autonomous at this point in time may be misleading, says Pressley, who prefers the term, “driver-assisted vehicles.” It’s important that people understand the limitations of these vehicles, she says. “We want to avoid giving the impression to the public that it is like air travel where you sit in a seat, watch your screen, and get where you’re going safely.”

The National Highway Traffic Safety Administration recognizes five levels of vehicle autonomy. At Level 0, the driver has full control. At Level 5, Google is testing a fully autonomous vehicle without a steering wheel or foot pedals. But for the near future, cars will be occupying intermediary levels; Ford, Toyota, and Volvo will soon be joining Tesla with their own semi-autonomous vehicles.

Racing Ahead

The research and regulatory communities have been playing catch up with manufacturers. According to Pressley, one challenge is that the data is largely limited to the actions of the driver—whether, for example, they were intoxicated or speeding. Increasingly it is becoming just as important to know about the road environment and the car—including the kind of software and combination of GPS and sensors it uses.

As a member of the Occupation Protection Committee for the Transportation Research Board of the National Academy of Science, Pressley joins manufacturers and government officials in planning for the future. “The testing is growing with the technology,” she says. “It requires coordination among the various groups.”

In September, President Barack Obama announced in a Pittsburgh Post-Gazette op-ed that his administration will issue new “rules for the road” for automated vehicles and pledged to put the brakes on any vehicle that is unsafe. This week, Pittsburgh hosts the first-ever White House Frontiers Conference, which convenes experts to discuss ways the public and private sector can collaborate to support innovation on and off the road.

Going forward, Pressley says the biggest safety gains could come through better testing and surveillance, as well as technology standards that allow vehicles to communicate with each other and with the road. One vision would allow for “car trains,” a caravan of cars that would automatically travel together on a highway—not a far cry from the World’s Fair vision from the 1930s.

A Different Animal

Approximately 35,000 people died in automobile crashes last year—94 percent due to driver error. Over the last 50 years, auto fatalities have dropped dramatically as cars added features like seatbelts and airbags. According to Peter Muennig, associate professor of Health Policy and Management, driver-assisted vehicles will further this downward trend. “These cars will reduce the probability of death and injury by a very large amount, even when there is no human behind the wheel,” he says.

Driver-assisted vehicles may be safer overall, but research suggests it is important to pay attention to the specifics around the crashes. According to Muennig, these incidents seem to be different than those involving a human driver. “These vehicles might be more likely to hit pedestrians, at least the kinds of pedestrians that pop out from between cars to jaywalk,” he says. “It’s kind of like releasing mountain lions to reduce deaths from deer collisions. The number of deaths goes down, but some people are eaten by mountain lions. There are ethical questions, but it is what we should be doing.”