Transportation planning is shifting from mobility-based to accessibility-based analyses to evaluate network performance. While mobility analyses essentially evaluate system performance based primarily on travel speed, accessibility allows planners to evaluate the system based on travel time. That is, how much time is required by different users to access desired services and activities such as work, school and shops. Accessibility takes into account speed, as well as distance between destinations, the different modes available, and the connectivity of the various networks.
MRCOG’s Transportation Accessibility Model (TRAM) works by demonstrating approximately how far one can travel along the existing network of roads and trails by mode (walking, biking, driving, or taking the bus) in a certain amount of time. By modifying the network, for example, adding a proposed bike path or road segment, the user can assess how new connections may improve access to various destinations. TRAM also allows the user to generate a market profile by extracting demographic and employment estimates for the area accessible to travelers within a specified travel time.