Delineation of light rail transit station service areas by mode of access using GIS: A case study of the Portland, Oregon Banfield LRT line

The overall objective of this dissertation was to gain a better understanding of the extent of the service area around an LRT alignment for daily commuters to the Central Business District (CBD). This was accomplished by using a Geographical Information System (GIS) to test a conceptual service area for a theoretical Light Rail Transit (LRT) alignment by comparing the assumptions used to develop this conceptual service area with the results of an on-board survey conducted on the Banfield LRT line in Portland, Oregon. The home-end of home-based work (HBW) and home-based school (HBS) trips were mapped using ARC/Info and ARC/View software for over 1800 surveys collected during the weekday in both directions on the Portland LRT system. In addition, the distance between each point and the corresponding boarding or alighting station was measured using the network module of ARC/Info. A separate telephone survey was conducted to better understand some of the motivations behind the behavior observed in the on-board survey.;Based upon the results of the two surveys, a spatial model of the service area around a 'typical' LRT alignment is presented. This includes separate analysis for walk-in patronage, feeder bus transfers and those who use an automobile to get to and from the LRT station. By understanding the underlying assumptions used to create this spatial model, transit planners can develop a map of the likely service area for a proposed LRT alignment. Knowing the service area can help in station location decisions, station design, feeder bus network design and the location of park/ride facilities. The service area can also help in the conduct of market research studies where there is a need to know the likely location of LRT users.