Just in time to make traffic worse, Google introduced its long-awaited self-driving cars Tuesday. The cars have two seats, no steering wheel, gas, or brake pedal—just a stop-and-go button. If all goes well, 100 to 200 of the cars are expected to be driving on California roads in a pilot program next year. The cars will max out at 25 mph and have sensors that can detect objects in all directions for up to 200 yards. “What I’m excited about is how we could change transportation today,” Google co-founder Sergey Brin said.