By now, everyone knows the rule: While driving, it's a big no-no to hold up a cell phone to your ear and chat away the commute.
That no-no got a lot more expensive since California implemented a hands-free law in July 2008. In the following months, motorists generally heeded the message, authorities say.
But a year and a half later, statewide data and anecdotal estimates suggest that drivers are falling back into bad habits, and it continues to be a common experience to spot people with one hand on the wheel and the other pressing a phone against their faces.
"This is one of those laws that was very well-advertised," said California Highway Patrol officer Tom Maguire. "When it happened, we saw people abiding by the rules."
Part of the reason for the initial good behavior, Maguire said, was that drivers knew police would be out en masse enforcing the new law. As that presence returned to normal levels, people shed their hands-free devices and went back to two-handed multi-tasking.
Maguire likened it to targeted speed enforcement on problem roads, which can briefly encourage drivers to abide by the speed limit because they know someone's watching.
"As in any enforcement action, when the presence goes away and the furor dies down, we see more violations," Maguire said.
Between May and October this year, the CHP issued 728 citations in Contra Costa County to drivers for violating the cell phone driving law, which prohibits phone use without a hands-free device. That total mostly covers two sets of violators: adults who talk without a hands-free device and minors who talk on a cell phone at any point while driving.
The tally also includes three citations for sending text messages while driving, which was prohibited at the beginning of the year but is much more difficult for police to detect.
"It's a lot harder to catch somebody," said Walnut Creek traffic Sgt. Mike McLaughlin. "We see people go by, looking down, focused on something ... . But unless we see them texting, we don't write (a citation). We don't want to write a citation that can't stand up in court."
Data indicates that as more time passed since the law's implementation, citations have steadily risen: the CHP recorded 90 violations on Contra Costa highways in May and a six-month high of 152 in September.
In the same six-month period, 14,001 citations were issued in the Bay Area, and were generally evenly spread, with a high of 2,855 citations in August. Texting citations accounted for just 77, or one-half of 1 percent. Statewide, 75,593 citations were issued, with 971, or just over 1 percent, coming by way of texting.
In Walnut Creek, as of November, 1,087 citations have been issued since the law went into effect, evenly distributed from month to month. McLaughlin said common excuses he hears from drivers are that the phone call was going to be quick, or that their Bluetooth headset wasn't working.
The base fine for a citation is $20. That can be somewhat misleading: After court and administrative fees have been added, the average true cost of a citation balloons to about $150, with the exact amount varying by jurisdiction.
"That buys a heck of a Bluetooth," McLaughlin said. "One to keep in every car."
McLaughlin pointed out another liability of cell phone use while driving: Call records can be easily obtained to argue a driver was on the phone, and possibly distracted, when an accident occurred, exposing that person to civil liability.
Maguire and McLaughlin also want to remind drivers about a key point of the cell phone law: hands-free means, well, hands-free.
"Some hold it out in front of them as a speakerphone, not thinking it's a violation," McLaughlin said. "There's no difference between holding (a phone) to your ear or six inches away from your ear as far as we're concerned."
Maguire put it more succinctly.
"If it's in your hand, it's not hands-free."
