Continuum Approximation Modeling of ADA Paratransit Operations in New Jersey

Providing paratransit service for people with disabilities is important for society. Transit agencies are further incentivized to provide such a service because provision of ADA complementary paratransit service is a prerequisite for transit agencies to be eligible for federal funding. This service is expensive to operate, so it is important understand the factors that drive these costs and to be able to predict the effect of changes in demand and service alignment on total operating costs. Thus, it is important to have accurate estimates of operating cost as a function of demand, service quality, and network characteristics. This paper presents three analytical models to estimate the required number of vehicles, the total vehicle hours operated, and the total vehicle miles traveled by paratransit vehicles in order to serve the demand. The three components are the major sources of operating cost. Another model is adopted to estimate the total cost based on aforementioned variables. The models used in this paper are continuum approximations based on geometric probability that relate physically meaningful and observable input values to the operating characteristics of interest. The calibration method requires only one parameter to be adjusted in order to fit the model to observed data. The models and calibration method may be applied to many similar paratransit services throughout the USA and around the world. For the case study of New Jersey, these models have been calibrated with the help of available databases. Eventually, estimations are employed to predict the costs for three prospective scenarios of demand growth, expansion change in service coverage, and a combination of both.