Chapter 21: GIS and the Collection of Travel Survey Data

Travel data are integral to transportation planning and policy decisions. Typically, these data are collected through some type of participant-based survey, which is a notoriously expensive and complex planning activity (Stopher, 2000). A fundamental requirement for useful travel survey data is that they are accurately related to specific geographic locations. This is achieved through a process known as geocoding, which involves the assignment of spatial identifiers (e.g. x, y coordinates, nearest intersection, traffic zone, census block) to activity/trip origins and destinations. Geocoding of survey data is arguably the most challenging aspect of data collection. This is primarily because of inaccuracies and omissions in both the reporting of addresses by survey participants and the address reference databases used in the matching process. In addition, these problems are being exacerbated by the growing demand for survey data with greater spatial precision to support the increasing use of disaggregate approaches in planning studies (Kreitz, 2001).