Drivers traveling in Santa Rosa Friday night and Petaluma Saturday night, heads up, police will be running DUI checkpoints in both cities.

Santa Rosa officers will be set up from 8 p.m. to 3 a.m. Saturday.

Petaluma officers will operate at two locations from Saturday night into early Sunday. They will split the time, running one checkpoint then moving everyone to a different location.

As is standard, police agencies don't release in advance where checkpoints will be located.

Law enforcement agencies conduct checkpoints routinely, stopping hundreds or sometimes thousands of drivers for a quick check to see if they could be impaired, either from alcohol or drugs.

They also check driver's for license status, looking for unlicensed drivers and those whose license has expired or been suspended.