RESULTS of a study of the characteristics of landside vehicle and pedestrian traffic at Miami International, Stapleton International, and LaGuardia Airports and one terminal at John F. Kennedy International Airport are presented. Vehicle and pedestrian flow rates at all terminal buildings, curbside areas, parking facilities, and airport entrance and exit roadways were measured simultaneously and related to levels of air-passenger activity by using enplanements and deplanements as indices. Processing time and service rates were also sampled at several locations at three of the four airports. These data were obtained at ticket counters, automobile-rental areas, passenger security checkpoints, parking cashier opreations, and other locations within the terminals. Representative per-passenger flow rates and processing times for pedestrians and vehicles are presented as rules of thumb to assist other airport planners.