Abstract:This paper addresses methodological issues in the estimation of travel-related impacts of telecommuting, based on findings from eight telecommuting pilot programs. Several of the studies address energy use (both travel-related and home-based) and one provides information on emissions of air pollutants. These findings are analyzed as well. Travel impacts examined include weekday person- and vehicle-miles saved due to a reduction in commuting, overall weekday travel reductions, and other changes in travel patterns for the telecommuter and the household. Some important issues regarding the estimation of these impacts, their use outside of the pilot programs, and their use in estimating energy savings or reductions in emissions are discussed. In particular, it is cautioned that early, short-term findings from small programs with participants unrepresentative of the population as a whole may change considerably as telecommuting moves into the mainstream.