Law enforcement officers will pay close attention to seat belt use through June 1 as part of the state's annual Click It or Ticket campaign.
During the campaign, which relies on heavy enforcement and public education, officers will check to make sure everyone in a vehicle is wearing a seat belt.
Fines are stiff. They vary from county to county, but first-time violations bring penalties from $80 to $91 for adults and from $330 to $401 for those under age 16, according to police.
California law requires every passenger in a car to wear a seat belt. Children 12 and under must ride properly restrained in the back seat.
Modesto police will target city drivers. The Stanislaus County Sheriff's Department will crack down in the county's unincorporated areas and in Riverbank, Patterson, Hughson and Waterford. The California Highway Patrol is participating, too. Manteca police also are involved. More than 280 law enforcement agencies statewide are involved in the campaign.
"Our officers will be on the lookout for those who are not buckled up and for teens and children not riding properly restrained. We will not accept excuses or give warnings," Turlock police Sgt. Bob Lugo said recently in a statement.
In 2007, California had the nation's fourth-highest seat belt use rate at 94.6 percent, according to state officials.
But teenagers had a much lower rate, at 88.9 percent, according to authorities.