The puget sound transportation panel after two waves

Abstract

Begun in 1989, the Puget Sound Transportation Panel is the first general-purpose travel panel survey in an urban area in the United States. The overall survey sample was stratified by county of residence and by usual mode of travel to work. This paper reports descriptive results from the first two waves of survey data. Panel attrition between these waves was about 19 percent of all households. There was some demographic bias in panel attrition. The paper documents changes among the retained households in their demographics, their residence and work locations, their trip making, their work trip lengths, and their travel mode to work. Residential moves were numerous among young adults and young families, more outward from the city core than inward, and correlated with changes in work trip length. Work locations changed for 20 percent of continuing workers, with a tendency to increase trips and work trip length, and to change travel mode after a relocation. For all workers, there were clear shifts from transit to drive alone, from carpool to drive alone, and from drive alone to carpool as well. The PSTP continues, with a modified third wave in 1991, and a fourth wave scheduled in 1992.