RACHEL MARTIN, HOST:
Self-driving cars have reached the point where they can predict what cars or bikes or pedestrians are going to do. And they lack the worst of human impulses. But until all cars are fully autonomous, sharing the road is still going to take some creativity. Margaret J. Krauss of member station WESA reports.
MARGARET KRAUSS, BYLINE: It wasn't a normal lunch break on Google's campus. But Nathaniel Fairfield says it wasn't supposed to be.
NATHANIEL FAIRFIELD: We asked a whole bunch of people to come and hop on bikes and ride around and around the vehicle to collect data.
KRAUSS: Fairfield is principal software engineer for Waymo, the self-driving car company that began life in 2009 as a Google project. By tracking a flock of cyclists, Waymo's cars were learning how bikes move through the world.
FAIRFIELD: That's not enough. You want to predict what they're going to do next. Cyclists, like pedestrians, are some of the most vulnerable road users. And so we do want to treat them with extra caution and care.
KRAUSS: Biking is the fastest-growing commuting choice in the United States. Nearly 1,000 cyclists were killed in car crashes in 2015, the most recent year for which data was available; 45,000 were injured.
Waymo's cars are programmed to pass bikes according to state laws, usually with 3 feet of clearance. And if they can't do that, they'll just wait. That kind of patience hasn't been lost on cyclists in Pittsburgh, one of three places where Uber is testing its fleet of self-driving cars.
ERIC BOERER: And honestly, I was predicting that people would be a bit more reluctant to ride around them or would be a little more critical of them.
KRAUSS: That's Eric Boerer. He's advocacy director for local pedestrian and cycling nonprofit Bike Pittsburgh.
BOERER: People did feel much more comfortable riding next to autonomous vehicles than they did next to human vehicles. I mean, autonomous vehicles - they don't get angry. They don't have road rage (laughter).
KRAUSS: The technology that helps make self-driving cars unemotional and conservative is showing up in today's cars. Forward collision warning or automatic braking systems help cars talk to one another and avoid collisions. But Anthony Rowe says they could use a little help when it comes to detecting cyclists.
ANTHONY ROWE: Cars have a very regular pattern with the way they move, whereas when people are riding bicycles, they change between either acting like cars on the side of the road... They might actually switch and become pedestrians and go up on sidewalks. They tend to move in a slightly more erratic way. It's much harder to predict.
KRAUSS: Rowe is an associate engineering professor at Pittsburgh's Carnegie Mellon University. And he wants to make it possible for bikes to feed information to cars - now and in the fully autonomous future.
ROWE: What we're trying to do is put as much instrumentation on a bike as we can to see if we can predict how it's going to move in the future so that it could, for example, signal a collision warning system on a car.
KRAUSS: Rowe pedals a white Bianchi Brava up and down a busy street near campus. The bike doesn't look particularly noteworthy, except for a slew of instruments...
ROWE: So we have a differential GPS unit, a small computer...
KRAUSS: ...Crowded where a rear rack might normally be.
ROWE: I would not be happy if I had to ride this every day. But hopefully, when all of this stuff just gets embedded in a cellphone on the front, then it should be no problem.
KRAUSS: Rowe and his team are looking for the least amount of data a car would need from a cyclist for it to trigger an automatic braking system.
ROWE: Even hundreds of milliseconds helps - right? - because if a car's going to slam on the brakes, it'll slow down dramatically by the time it crashes into you.
KRAUSS: Rowe thinks self-driving cars will make the future a lot safer for cyclists and pedestrians. But while humans remain the primary pilots, he thinks a little help from bikes could compensate for their weaknesses. For NPR News, I'm Margaret J. Krauss in Pittsburgh.
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