Most testing, however, is being done in California, where Google was the pioneer in the autonomous-vehicle industry. Uber, the ride-hailing service, is attempting to start autonomous vehicle service in San Francisco and Pittsburgh. The legality of that service, however, remains unresolved as regulators continue to consider whether driverless services should be permitted.

Uber, engaged in a clash with California regulators, said last month that it would end its autonomous-vehicle program in San Francisco and relocate the self-driving service to Arizona. Also last month, Uber asked the Pennsylvania Department of Transportation to delay guidelines for driverless cars pending legislation in the state, according to sibling publication The Legal Intelligencer.

Jessica González, a spokeswoman for the California Department of Motor Vehicles, said 20 automakers have been granted permits to test autonomous vehicles, and must post $5 million in insurance or bond or self-insurance. At present, she said, regulations regarding insurance requirements for the general use of autonomous vehicles have not been written in the state.

Anticipation NJ will permit driverless vehicles

The New Jersey Assembly bill, A4504, is sponsored by Assemblywoman Pamela Lampitt, D-Camden, and Assemblyman Arthur Barclay, D-Camden. The Senate bill, S2895, is sponsored by Sen. Nia Gill, D-Essex. No hearings have been scheduled for the bills.

Lampitt said she introduced the legislation in anticipation that, at some point in the future, New Jersey will permit the general use of driverless vehicles. Gill did not return a telephone call seeking comment.

Gov. Chris Christie's office generally does not comment on legislation until it reaches his desk.

New Jersey currently requires a minimum of $15,000 coverage per person and $30,000 per accident.

"It [the general use of autonomous vehicles] will happen eventually, but there are a lot of questions that have to be answered," Lampitt said. The central question, she said, is whether someone who is riding in an autonomous vehicle, who may own the vehicle but is not at the controls, should be held responsible in the event of an accident.

Legal landscape uncertain

Currently, she said, it appears that the manufacturer of the vehicle would be held liable, but the legal landscape is uncertain.

"We're looking to make sure that insurance is available if no one is behind the wheel," Lampitt said. "We're looking to who coverage should go back to, and creating a process for manufacturers to follow."

State and federal rulemaking on autonomous vehicles is expected to accelerate this year, as carmakers and others push for more consistency, as reported in sibling publication Legaltech News.

New Jersey lawmakers have introduced a bill that would require owners of driverless cars to maintain liability insurance coverage, instead of operators.

Related: Driverless cars: What are the insurance implications?

Michael Booth is the Trenton Bureau Chief for the New Jersey Law Journal. You can contact him at [email protected].