On the verge of wider public testing, the self-driving car company Waymo is touring Midpenisula cities to showcase its technology. On Dec. 13, the Waymo delegation came home to Mountain View, meeting with a packed crowd anxious to learn more about the company's driverless vehicles. Attendees heard from company officials and got a chance to look at one of its cars.

The big question on everyone's mind was: "When will these be available to ride in?" But that wasn't something the Waymo team would answer. George Ivanov, Waymo public policy manager, could only say it would be "a while" before the self-driving cars will be available to the public in California. He pointed out that just days earlier, Waymo launched its free "Waymo One" pilot for the public in the Phoenix area and said the company is watching how that program proceeds.

Since October, Waymo has been authorized by state regulators to send its vehicles out onto public streets with no human drivers on board. As the technology is being tested, California regulators are allowing autonomous car companies such as Waymo to offer the public rides in its vehicles so long as it doesn't charge for the privilege.

Waymo officials said they were finished drafting an interaction plan for law enforcement agencies. Mountain View police officials say that Waymo has offered to hold training sessions for officers.

A main theme at the Dec. 13 Waymo meeting was safety and the untapped potential for autonomous vehicles to reduce U.S. traffic deaths. Each self-driving car is equipped with an array of sensors that can detect potential hazards quicker than the human eye, Waymo officials said. In some cases, that could lead a Waymo car to drive extra cautiously, to the frustration of any human drivers following behind. Often, the Waymo car is detecting potential hazards that a human driver would completely miss, Waymo officials said.

Yet there are times when even a self-driving car programmed to abide by the Department of Motor Vehicles driver handbook must break the rules. Waymo cars are designed to improvise in certain situations, such as driving with the flow of traffic or veering out of a lane to avoid construction zones.

"For safety reasons, we sometimes break the rules. There are times when following the rules actually might impact safety," Ivanov said.

For the time being, Waymo intends to maintain ownership of all vehicles equipped with its technology. There are no plans to sell self-driving cars to individual consumers, as that could present problems for ongoing maintenance, said Ellie Casson, Waymo local policy head. The company's plan for now is to operate as a ride-sharing service like Lyft or Uber.

"For now, we'll take you from point A to point B, but you won't be able to buy a Waymo vehicle," Casson said. "But in the future, who knows?"