The majority of traffic laws apply to bikes. Regulatory signs, right-of-way rules, and traffic signals apply to cyclists as well as motor vehicles. Bicycles are also required to have working brakes and use headlights at night or in inclement weather. Bikes are required to operate as close to the right side of the roadway as can be safely done (riding in the gutter portion of a curbed road is not safe). Where it is legal for cyclists to ride on sidewalks, they are subject to the same laws as pedestrians. Under a selective enforcement policy for bicycles, the most logical strategy is to target those violations that most often result in car-bike crashes. The top three car-bike crash types that involve adult cyclists are the motorist stop and go (traffic lights and stop signs), the unexpected left turn by the cyclist or the car, and a motorist overtaking a cyclist from the rear moving in the same direction. The top three car-bike crash types that involve children are usually the result of the child's actions. These include riding out of a driveway or alley; riding through an intersection against a light or stop sign; and a sudden unexpected swerve into a car's path. When a patrol officer observes any car or bike maneuvers that could have resulted in a crash under certain circumstances, a citation or warning should be given. The article also discusses officers' enforcement of bicycle traffic laws to stop and search bicycles and cyclists suspected of being couriers for illegal drugs.