Institute for Transportation

About the research

This project developed a computerized system to support decisions about how to locate facilities that serve rural areas while minimizing transportation costs. The work is based on the premise that transport systems should be efficient—that is, the lower the total transport costs, the better the transportation plan is. The computerized system integrates transportation databases with algorithms that specify efficient locations and allocate demand efficiently to service regions; the results of these algorithms are used interactively by decision-makers. They can introduce or relax constraints and reject solutions on the basis of their informed judgments about what will work.

This spatial decision support system is suited to solving semi-structured problems—those in which decision-makers do not know at the outset what criteria are relevant, what their appropriate weights are, or what the site-specific constraints are. Using the system, decision-makers can vary the objectives they specify for the transportation plan and immediately see the resulting patterns for locating facilities on system-generated maps.

The project developed documentation for the system so that others could apply it to estimate the transportation and route requirements of alternative locations and identify locations that meet certain criteria with the least cost. The project developed and tested the system on two transportation-related problems in Iowa, and this report uses these applications to illustrate how the system can be used. More generally, the project demonstrates the type of support that decision-makers need in making locational decisions.