SACRAMENTO — As electronic highway billboards flashing neon advertisements become more prevalent, the next frontier in distracted driving is already approaching — ad-blaring license plates.

The California Legislature is considering a bill that would allow the state to begin researching the use of electronic license plates for vehicles. The move is intended as a moneymaker for a state facing a $19 billion deficit.

The device would mimic a standard license plate when the vehicle is in motion but would switch to digital ads or other messages when it is stopped for more than four seconds, whether in traffic or at a red light. The license plate number would remain visible at all times in some section of the screen.

In emergencies, the plates could be used to broadcast Amber Alerts or traffic information.

The bill's author, Sen. Curren Price, D-Los Angeles, said California would be the first state to implement such technology if the state Department of Motor Vehicles ultimately recommends the widespread use of the plates. He said other states are exploring something similar.

Interested advertisers would contract directly with the DMV, thus opening a new revenue stream for the state, Price said.

Price said the devices also would cut costs by streamlining the distribution, activation and registration of license plates.

The legislative analysis of Senate Bill 1453 does not include estimates of how much revenue could be saved or gained from license plate advertising.

At least one company, San Francisco-based Smart Plate, is developing a digital electronic license plate but has not yet reached the production stage.

Reached by e-mail Friday, the company's chief executive, M. Conrad Jordan, said the legislation provides an opportunity for the state to harness some of the creativity and technical expertise of its private sector.

Jordan said he envisioned the license plates as not just another advertising venue, but as a way to display personalized messages — broadcasting the driver's allegiance to a sports team or an alma mater, for example.

"The idea is not to turn a motorist's vehicle into a mobile billboard, but rather to create a platform for motorists to show their support for existing good working organizations," he said.

The bill would authorize the DMV to work with Smart Plate or another company to explore the use and safety of electronic license plates — a process that would include consultations with the California Highway Patrol, Price said.

CHP spokeswoman Fran Clader said the agency has not taken a position on the legislation. A spokeswoman for Gov. Arnold Schwarzenegger said he also will remain neutral until the bill reaches his desk.

Any cost associated with the initial research would be borne by the company, not the state, Price said.

The DMV would be required to submit its findings and recommendations to the Legislature by Jan. 1, 2013.

The bill has received no formal opposition. It passed unanimously through the Senate last month and is scheduled to be heard today by the Assembly Transportation Committee.