GIS platform for multicriteria evaluation of route alignments

The selection of an appropriate alignment for a proposed highway is determi ned largely by relating topographic, urban, and environmental features to g eometric design controls. Typically, aerial photographs and topographic, ge ologic, and soil maps are reviewed. In this paper, a geographic information system (GIS) platform that incorporates the main coverages needed for eval uating route alignments is described. Using the GIS and a geographically re ferenced database, a decision-aid tool for multicriteria evaluation of rout e alignments is developed. Possible alignments are evaluated based on commu nity disruption and environmental, geotechnical, and geometric design crite ria. The developed decision-aid tool integrates slope stability and roadway design packages and specifically written codes with GIS packages ARC/INFO and ArcView, the latter acting as the system engine and interface. A case s tudy is presented that applies the developed platform to the testing of pot ential alignments for a proposed 12 km highway to the south of the city of Beirut, Lebanon. Results of the case study demonstrated the advantages of t he decision-aid tool and highlighted its potential in providing a quick, mu lticriteria screening evaluation of possible route alignments.