A law banning text messaging while driving took effect on Thursday, the California Highway Patrol (CHP) announced, Xinhua reported.
Under the law, writing, sending or reading any text-based messages on a cell phone or any type of wireless communications device, like a Blackberry or laptop computer, by a driver will be a violation subject to a 20-dollar fine on the first offense and 50 dollars for subsequent violations.
The ban applies to drivers even while their car is stopped.
"Motorists may not text at a stoplight," CHP spokeswoman Fran Clader said. "They are still operating a vehicle and need to focus their attention on the safe operation of that vehicle."
The CHP said it is not offering any grace period to drivers in enforcing the new law.
The new law is intended to complement the state's hands-free cell phone law which took effect in July last year.
Since last July, the California Highway Patrol has issued more than 40,000 tickets to drivers who have used their phones.