A methodology to estimate the demand for essential services by enumeration district is developed. The framework of the methodology considers total demand for essential services and associated transportation to be the sum of latent and satisfied demand. The origins of latent demand are indicated by examining the barriers which must be overcome by an individual to satisfy an existing need. The method for estimating satisfied , demand begins with census data by enumeration district. Actual usage rates of a service, cross-classified by factors influencing actual usage such as age, sex, race, and income are obtained from national surveys and then applied to the local census data to obtain an estimate of satisfied demand for the service by enumeration district. The methodology was used to estimate the satisfied demand for hospital care and was found to be accurate to within 7/10 of one percent for the study region. Total demand for a service may be estimated in a similar fashion by substituting barrier-free usage rates in the above methodology. Latent demand by enumeration district then became the difference between total and satisfied demand. The total transportation associated with a service system is obtained by assigning the demand by enumeration district to the closest facility up to its capacity with spillovers to the next closest facility. Total travel is then calculated using these origin-destination links and the frequency of trips.