DEVELOPMENT OF A DEMAND SCREENING TOOL FOR EXPANSION OF EXISTING OR CREATION OF NEW PARK AND RIDE FACILITIES

摘要

Facilitating transit usage is a critical part of maintaining mobility. If transit service is not within walking distance, park and ride accommodations are necessary. Expanding highly used lots can be costlier and less feasible than creating greater additional capacity at new locations. An expeditious method of screening for demand at potential new locations is needed. The method described herein performs that function, using GIS methodology to quickly develop demand estimates for new lots, as well as unmet demand at existing lots. The method uses readily available census data, as well as commonly available lot capacity and usage data. Survey data or model capabilities are not required. The method can be calibrated to observed usage, and is intended to be sensitive to local conditions and transit service levels. The procedure uses tract level resident worker quantities, and allocates these to segments of geometric shapes, each of which is tagged with market capture percentages. Road buffering is used to separate out developable land for use in allocation. Shape orientation may be set, and overlap of market areas corrected. Calibration is accomplished by comparison of estimates with usage of existing facilities, and adjustment for transit service characteristics and accessibility as observed within the study area. Evaluation of results for 29 lots in three bus corridors, and 20 lots in two rail corridors, indicated very close correlation of predicted with expected values. Consistency was seen, with outliers attributed to service or accessibility deficiencies and lot capacity constraints, as expected.