Sonoma County police agencies today are joining with dozens of departments around the state in the latest crackdown on drivers texting or not going hands free on their cellphones.

Santa Rosa police, for example, will have 18 officers today devoted to looking for violators, Sgt. Rich Celli said. Of those, four will be bicycle officers who patrol the downtown area.

Today’s crackdown is part of a month-long, stepped up enforcement of the state’s cellphone and texting laws. In the first week of the crackdown, Celli said, Santa Rosa officers averaged about 100 tickets a day but that number has tapered off since.

If you figure those 100 tickets were for first-time offenders, whose fine totals $160 each, the officers were writing tickets worth a total of $16,000 each day. The fine jumps to $280 a ticket for subsequent violations.

But before you jump to the conclusion that Santa Rosa’s getting rich off these tickets, consider that the city gets only 85 percent of the $20 base fine for first offenders. That’s $17 a ticket. The rest of the fine goes to the county and state because of numerous fees and surcharges that the Legislature has added to traffic tickets. Subsequent violations carry a base fine of $50 but a total cost of $280 with all of the fees.

State Sen. Joe Simitian, D-Palo Alto, has revived his campaign to increase fines for cellphone use and texting by drivers — and bicyclists.

He’s re-introduced legislation that would raise the base fine of a driver’s first violation to $50, which with fees would total about $300 a ticket, and the base fine for subsequent violations to $100, which with fees would be about $500.

His bill also would add a penalty point on motorists’ driving records for repeat violations of the hands-free cellphone law and would apply the cellphone and anti-texting laws to bicyclists. But bicyclists would only pay $20 total for a first offense and $50 total for subsequent and would not receive points on their driving record.