Estimating functional population for facility planning

In estimating the current and future demand for facilities, engineers and planners need to rationalize differences in facility demand by land-use category. Using unweighted population and employment data to estimate facility needs may result in substantial error. The solution is to properly weight population and employment figures to create a common unit of measure, the functional population, defined as the number of people occupying space in the community on a 24 hr per day, seven-day-per-week basis. By estimating the functional population of a community, estimations of current and future demand for certain facilities can be improved. This paper offers a reasonably convenient method for estimating the functional population for a current and future year. It applies the functional population concept to estimating the current and future demand for fire protection, police, emergency medical, jail and detention, courts, and government administration facilities for a hypothetical community.