The Missouri Department of Transportation (MoDOT) employed ArcView 3.1 software from ESRI through an enterprise-wide Geographic Information System (GIS) to identify environmental constraints to expanding I-70. Geographic information on historic buildings and bridges, archaeological sites, cemeteries, roads, wetlands and streams, floodplains, public lands, and sensitive biological resources was used to produce a series of coverages along I-70 from Kansas City to St. Louis. While documenting the feasibility of improving I-70, MoDOT considered the following issues: the availability of resources for geographic data, the level of detail and extent of coverage needed for the project study area, and the techniques for updating topographic map information. MoDOT produced a map in 36 plates to cover the project study area and found two areas along the facility with a concentration of environmental constraints. GIS and the resulting feasibility study were used to help MoDOT determine that a tiered environmental document was needed to evaluate alternatives to expanding I-70.