For existing facilities, parking shortages can be identified by conducting a parking utilization study. This study compares the highest number of vehicles parked at each facility to the available parking supply. The survey should be conducted at least twice daily, 10 a.m. and 2 p.m. for long-term parking; and every 1 to 2 hours during business periods for short-term parking. Areas such as base exchanges and food courts should be surveyed during the lunch hour. Areas such as commissaries should be studied during peak shopping time periods, which may include weekends. SDDCTEA Pamphlet 55-8 provides more information on data collection procedures.
Generally, short- and long-term parking areas should not be more than 85- and 90-percent full, respectively. Should the parking utilization rate exceed these figures, consider additional parking.
Future parking demand can be determined by using parking generation rates. A parking generation rate equates parking demand to a predictable characteristic, such as population, number of employees, or floor space. These rates have been developed for many types of facilities and are published in the Institute of Transportation Engineers' (ITE) Parking Generation manual.
It is also recommended that installations review service-specific regulations to consider the authorized number of parking spaces based on facility type.