A cost effectiveness evaluation and a cost-benefit analysis were performed on a park-and-ride system consisting of 26 park-and-ride lots in the Seattle metropolitan area. Costs and benefits of the system were examined with respect to the user, the community at large, and the public agencies responsible for providing for the community's transportation needs.
A user survey was conducted at the 26 lots. Using the survey data and other data as input, a model was developed to calculate the total incurred trip costs of both the park-and-ride trip and the corresponding trip not involving the park-and-ride lot. These trip costs were compared in a "before" and "after" analysis. In addition, the park-and-ride system was analyzed for its effect on the following transportation system measures of effectiveness: travel time, person miles traveled (PMT), vehicle miles traveled (VMT), traffic volumes, vehicle emissions, accidents, and energy consumption.
General results indicated that the park-and-ride system in the Seattle area is cost effective. The average park-and-ride trip was estimated to be 11.6 percent less expensive than the corresponding average previous trip by another mode. Results also indicate that the lots have had a slightly negative impact on travel time and PMT (i.e., these measures have increased), but VMT, traffic volumes, accidents, vehicle emissions, and energy consumption have all been reduced.