These laws augment the California Highway Patrol's extensive anti-DUI (driving under the influence) efforts. The use of sobriety checkpoints is an effective DUI tool in California. The California Supreme Court has listed key safeguards to establish reasonableness of sobriety checkpoints under the Fourth Amendment. These include a neutral formula to determine which vehicles will be stopped and insuring that the safety of motorists and officers is given top priority. Other safeguards include only detaining stopped motorists long enough for the officer to question the driver briefly and to look for signs of intoxication. It is also necessary to give advance publicity before a checkpoint is set up. Another possible tool that could be used against drunk drivers is the preliminary alcohol screening device. It was decided, however, not to use it because it is in conflict with the designated driver programs which the California Highway Patrol supports.