The six-mile stretch of the Stevenson Expressway (I-55) between US Route 30 and Weber Road currently has only one interchange, consisting of a northbound on-ramp and a southbound off-ramp at IL Route 126. In accordance with NEPA requirements, our team provided Phase I engineering services for two full-access interchanges in Will County, IL. Our services included traffic projections, traffic modeling, geometric studies, interchange and intersection design studies, access justification report, environmental assessment, combined design report, traffic management analysis, bridge condition evaluations, and location drainage study. The preferred build alternative includes a new full access interchange at Airport Road and a reconfigured interchange at IL 126, providing full access.