Raj Rajkumar, who heads the Carnegie Mellon University driverless car research project, said he believes “only sometime in the 2020s will a fully autonomous system that does not require a human to be in the driver’s seat become feasible.”

He said the cars can eventually revolutionize transportation. Rajkumar urged policy makers to go slow. “We should exercise caution in rushing to deploy technologies before ensuring that they can be trusted. For the foreseeable future, a human must continue to sit in the driver’s seat even if the vehicle is driving itself,” he said.