Extensive research in alcohol related projects has determined that the general deterrence approach has the greatest potential for achieving a substantial, short-term reduction in alcohol related crashes. General deterrence programs are those designed to raise the perceived risk of arrest and sanctioning by the vast majority of drunk drivers who are never arrested; checkpoints are an effective component of an enforcement system designed to raise perceived probability of an arrest for DUI.
Locations are selected on PennDot statistics: accidents, fatal accidents, and alcohol related accidents. All vehicles enter into the checkpoint and are briefly stopped. A 15-20 minute conversation is held with an officer. If nothing is immediately detected the operator is permitted to pass through. If detection occurs, the driver is directed to move to a second location for further investigation (Standard Field Sobriety Test, Portable Breath Test, Identification/Ownership); based on these processes, arrest may or may not occur.