Corridor coalitions have provided the necessary framework for the deployment of Intelligent Transportation Systems on a corridor-wide basis. The new federal transportation bill of 1997 is projected to support this type of planning application well into the next century, and there will be a growing need to define corridor boundaries as more coalitions are formed. A methodology to set these corridor boundaries quickly and without elaborate data collection is necessary as planners begin to analyze a particular corridor’s needs.

The proposed methodology presented within this report uses shortest path criteria and macroscopic traveler modal choice to fulfill these requirements and defines the potential market of users for I-81. Since origin-destination data is not readily available, the geographic location of cities in relation to a particular interstate highway becomes important as one defines the interstate’s influence upon a particular city to attract trips. In this study, the criteria for a major origin or destination to be included in the corridor are based upon three parameters:

City size must be over 50,000 in population The Origin - Destination (O-D) pair must use I-81 O-D pair must be within the shortest path distance of 368 miles

By using the proposed methodology to define the corridor boundary, 85% of the automobile travel and approximately 78% of the truck travel have an origin or destination within the corridor boundary. Future research and validation of this boundary definition needs to be performed before this definition can be fully accepted.