SACRAMENTO — Get ready to remove your fingers from that tiny keyboard while driving.

Gov. Arnold Schwarzenegger on Wednesday signed into law a measure banning motorists from text-messaging and e-mailing while operating a vehicle.

The law, written by Sen. Joe Simitian, D-Palo Alto, takes effect Jan. 1.

“Building on legislation already helping save lives in California, I am happy to sign this bill because it further encourages safe and responsible driving,” Schwarzenegger said in a statement. “Banning electronic text-messaging while driving will keep drivers’ hands on the wheel and their eyes on the road, making our roadways a safer place for all Californians.”

Drivers caught using their phones to write, read or send messages will be hit with a $20 ticket the first time and $50 on each subsequent offense. The penalty is a base fine, which is uniform across the state, but does not include the fees added by local municipalities.

Simitian also is the author of the law that requires motorists to use hands-free devices if they chat on the phone while driving. That law went into effect July 1.

He intended to ban texting shortly before the Legislature approved the hands-free law in 2006, but decided against including the provision in order to improve the hands-free bill’s chances of passage.

In pushing for the texting bill, Simitian cited a study that showed that the majority of people who text-message in the United States, also did so while driving.

The texting legislation, SB 28, introduced in June, received overwhelming support in the Legislature.

“Texting while driving seems so obviously unsafe, it’s hard to believe anyone would attempt it, yet everyday observation tells us it’s all too common,” Simitian said. “I think this bill is a lifesaver.”

Driver-safety proponents praised the law, though some said the fine is too small.

“I think it ought to be $500 or $1,000 for the first time, and double every time thereafter; it’s the only way to get people’s attention,” said Steve Smith, a consultant to IBM and San Jose resident who gets irked when he sees drivers texting or talking into the phone. “It’s clearly not a deterrent at $20,” he added, “nor is it worth our enforcement time to hand our $20 tickets.”

Simitian said the $20 base fine, which is the same amount for violating the hands-free law, “is likely to cost you close to $100 out of pocket,” once penalties and court costs are added.

A third law proposed by Simitian and signed by Schwarzenegger, which took effect July 1, prohibits drivers under the age of 18 from operating a cell phone — whether using voice or text — at the steering wheel of a moving car.

Contact Edwin Garcia at egarcia@mercurynews.com or (916) 441-4651.