Autonomous vehicles face years of problem-solving
PITTSBURGH — In the world of autonomous vehicles, Pittsburgh and Silicon Valley are bustling hubs of development and testing. But ask those involved in self-driving vehicles when we might actually see such vehicles carrying passengers in every city, and you will get an almost-universal answer: No time soon.
An optimistic assessment is 10 years. Many others say it will be decades, as researchers try to conquer a number of obstacles. The vehicles themselves will appear first in limited, wellmapped areas in cities.
A fatal crash involving an Uber autonomous vehicle in Arizona in March slowed progress, largely because it hurt the public’s perception of the safety of vehicles. Google’s Waymo responded by deciding not to launch a fully autonomous ridehailing service in the Phoenix area and will rely on human backup drivers to ferry passengers, at least for now.
Here are the problems that researchers must overcome: Snow and other weather problems
When snow is heavy enough to cover the pavement, it blocks the view of lane lines that vehicle cameras use to find their way. Researchers have yet to figure out a way around this. That’s why much of the testing is done in warm-weather climates such as Arizona and California.
Heavy snow, rain, fog and sandstorms can obstruct the view of cameras. Light beams sent out by laser sensors can bounce off snowflakes and think they are obstacles. Radar can see through the weather, but it doesn’t show the shape of an object needed for computers to figure out what it is.
“It’s like losing part of your vision,” says Raj Rajkumar, an electrical and computer engineering professor at Carnegie Mellon University.
Researchers are working on laser sensors that use a different light-beam wavelength to see through snowflakes, said Greg Mcguire, director of the Mcity autonomous-vehicle testing lab at the University of Michigan. Pavement lines, curbs
Around the world, roadmarking lines differ or do not even exist. Lane lines aren’t standardized, so vehicles have to learn how to drive differently in each city. Sometimes there are no curbs to help vehicles judge lane width.
For instance, in Pittsburgh’s industrial “Strip District,” where many selfdriving vehicles are tested, the city draws lines across the narrow lanes to mark where vehicles should stop for stop signs. Sometimes the lines are so far back and buildings are so close to the street that autonomous cars that stop at a line can’t see traffic on the cross street. One workaround is to program vehicles to stop for the line and creep forward.
Humans
For many years, autonomous vehicles will have to deal with humans who don’t always play by the rules. They double-park or walk in front of cars. Recently in Pittsburgh, a backup driver for autonomous-vehicle company Argo AI had to take over when his car stopped during a right turn, blocking an intersection, because it couldn’t immediately decide whether to go around a double-parked delivery truck.
“Even if the car might eventually figure something out, it’s shared space, and it’s socially unacceptable” to block traffic, said Pete Rander, president of Argo AI, in which Ford has invested heavily.
Humans also make eye contact with other drivers to make sure they’re looking in the right direction, an ability still being developed for autonomous vehicles.
Left turns
Deciding when to turn left in front of oncoming traffic without a green arrow is one of the more difficult tasks for human drivers, and one that causes many crashes. Autonomous vehicles have the same trouble.
Waymo CEO John Krafcik said in a recent interview that his company’s vehicles are still encountering occasional problems at intersections.
“I think the things that humans have challenges with, we’re challenged with as well,” he said.