Modeling the Spatial Effects on Demand Estimation of Americans with Disabilities Act Paratransit Services

A reliable method for predicting paratransit ridership is important, especially for the efficiency of the services offered. The commonly used aggregate regression model is most accurate for forecasting the total demand for regional areas such as whole counties or cities; however, it is likely to be geographically inaccurate. This paper proposes a geographical weight regression (GWR) model for predicting the demand for the types of paratransit services required by the Americans with Disabilities Act. The GWR model reflects better the characteristic of each area having its own coefficient for predictors rather than the same value throughout. The results show that trip demand increased proportionately to (a) the population size, (b) the ratio of senior citizens, (c) the ratio of people below the poverty line, and (d) the ratio of African-American riders. These results suggest that the predictive performance of the GWR model is better than that of the ordinary least squares (OLS) regression model. The GWR model is of greater value than the OLS model to researchers and practitioners, because the predictor variables are readily available from census data; this availability of data allows researchers to use the model after calibration