Interstate 255 (I-255) is a 30 mile long bypass route that runs through Illinois and Missouri. Oates Associates’ involvement began in the 1980s with the development of aesthetic guidelines for the design of all visual elements in the highway complex (including bridges, sign structures, fencing, guardrail, landscaping and grading).

Oates was awarded subsequent contracts to design extensions of I-255. In total, 6 miles of interstate and 10 major bridge structures, along with the I-255 / I-270 interchange and a new interchange with a county road were designed. Significant maintenance of traffic was required as well as seismic analysis for structure design.

Project Stats

Interstate 255
Madison and St. Clair Counties, Illinois
Construction Cost: $70,000,000+
Completion Date: Multiple Projects
Client: Illinois Department of Transportation