The Local Index of Transit Availability (LITA), developed by Rood (1998) for the Sacramento-based Local Government Commission, is one of the more comprehensive performance measures as it combines three aspects of service: route coverage (spatial availability), frequency (temporal availability), and capacity (comfort and convenience).  By relating the amount of transit service in an analysis zone to the population (residents and employed) in the zone, the LITA addresses both the supply and the demand of the service in one composite LOS score.  The computation of the overall LITA score involves first calculating separate scores for route coverage, frequency, and capacity.  The service coverage score is given by the number of stops in a zone divided by the square mileage of the land area in the zone.  The frequency score is defined as the total number of transit vehicles for the line.  The capacity score is in seat-miles per capita, calculated as total daily seats on a transit line (which is vehicle capacity multiplied by number of vehicles per day) multiplied by route-miles of transit line in zone, and then divided by the total population in the zone (residential population plus worker population).  Each of these three scores is then standardized across all the zones in the study area to provide a measure of relative accessibility.  The standardization is achieved by (1) taking the difference between the raw score and the mean of the distribution and (2) dividing the difference by the standard deviation of the distribution of that score.  The overall LITA score is the average of the three standardized scores.  For ease of interpretation, the authors add 5 to the overall score so that the score is always positive and takes a value from 1 to 10.  The adjusted score is then mapped to grades A through F, with grade “A” corresponding to an adjusted score of 6.5 or higher, indicating the highest level of accessibility.