Abstract
The effects on vehicular speeds of two positions of a single patrol vehicle were studied in or adjacent to the traffic stream on rural roadways in North Carolina. A single stationary patrol vehicle was packed adjacent to the roadway in a position visible to oncoming traffic; the other was moving in the stream of traffic. The collected data were analysed. They indicate that there is a reduction in speed in case of the stationary patrol car, but that there is no significant change when the moving patrol unit was introduced.