An early warning requirement for DUI checkpoints pushed by a Santa Rosa legislator has encountered stiff resistance from local police officials.

The bill, by Democratic Assemblyman Michael Allen and now before Gov. Jerry Brown, would require police to announce the exact location of DUI checkpoints two hours before they are held. It also would require 48-hour notification of a checkpoint's general location.

Such advance notice would hamper efforts to catch drunken drivers at checkpoints, said Petaluma Police Chief Dan Fish.

"It takes away the effectiveness of the checkpoint," Fish said. "Drunk drivers are not going to drive through the checkpoints, they're going to drive somewhere else."

The issue centers on the dual enforcement of both DUI and driver's license laws that comes at checkpoints.

Allen has argued that while the purpose of the checkpoints is to reduce drinking and driving, the stops often catch more drivers who do not have licenses.

Originally, the measure, AB 1398, included language that would have ended the police practice during DUI checkpoints of impounding for 30 days vehicles driven by unlicensed drivers.

That language was dropped and recast as AB 353, with Assemblyman Gil Cedillo, D-Los Angeles, as author and Allen as co-author. AB 353 also is before the governor.

The bills are aimed at providing some relief to illegal immigrants, who are disproportionately affected by the 30-impound rule because they are not allowed to obtain driver's licenses in California.

The state vehicle code calls for impounding vehicles for 30 days if driven by unlicensed drivers or drivers whose licenses have been revoked or suspended. The legislation maintains the 30-day impound rule for those with suspended or revoked licenses.

Such checkpoints have been held multiple times on Sonoma County roads this year, the latest Friday night in Petaluma.

Police conducted two checkpoints, the first on Sonoma Mountain Parkway and the second on Petaluma Boulevard North at Gossage Avenue.

A total of 987 vehicles were screened and no drivers were found to be driving under the influence of alcohol or drugs. Three drivers were arrested for driving without licenses and two were arrested for driving on a suspended license. Four vehicles were towed, and three of them were impounded for 30 days, Petaluma police reported.

Sebastopol Police Chief Jeff Weaver said AB 353, as written, is a bad idea.

"Because of the way this law is written, it would allow multiple-time unlicensed drivers to avoid the impoundment of their car," Weaver said.

Barring any other violation at the time of the checkpoint encounter, such as outstanding warrants, false ID or probation or parole violations, Weaver said officers would not be able to take someone into custody unless the person could not provide "satisfactory ID."

Richard Coshnear, a Santa Rosa immigration attorney and a member of the Sonoma County Committee for Immigrants Rights, said the court fines and impound fees are the real punishment.

He said the 30-day impound rule is supposed to be an administrative procedure "to protect the community, not to punish the driver."

The checkpoints follow a number of guidelines taken from a 1987 state Supreme Court ruling and that are spelled out in Allen's legislation.

They include:

; DUI checkpoints could not be combined with vehicle inspection checkpoints.

; The checkpoint location would be based on a high incidence of DUI arrests or a high volume of DUI-related accidents.

; The checkpoint must either stop all vehicles or use a neutral methodology for determining which vehicles to stop.

Fish said local checkpoints already follow these court-ordered rules.

Under the bill, motorists would be allowed to avoid the checkpoint by making a safe and legal turn out of the checkpoint route.

Allen was unavailable for comment Thursday or Friday.

His spokesman, David Miller, said the intent of AB 1389 is to ensure DUI checkpoints focus on drunken driving as well as to ensure checkpoints are conducted under uniform guidelines.

"It's great that some communities across the state are already following the guidelines as laid out by the court but others are not," he said.

Brown has until Oct. 9 to take action on bills sent to him by the Legislature. His office does not comment on what action he will take.

You can reach Staff Writer Martin Espinoza at 521-5213 or martin.espinoza@pressdemocrat.com.