John Dolan, principal systems scientist at Carnegie Mellon University’s Robotics Institute in Pittsburgh, suggests that the different systems offer different levels of ability to see through storms. A camera, obviously, is the least effective. But the radar? “The snow shouldn’t really bother the radar,” Mr. Dolan said. “That is pretty weather impervious, and the snow is not going to confuse it.” But its drawback is the blob of a picture it reports back to the computer. Lidar, though, can be easily confused, he said. He pointed to dust devils — sandstorms in desert areas — that pretty much set current autonomous vehicles to parking by the side of the road. “I think the snow is going to cause some problems that you can’t simply write off by virtue of having lidar and GPS,” Mr. Dolan said.