Designed in the 1950s prior to the development of Interstate Highway System design standards, I-74 was one of the oldest freeways in Illinois. The Illinois Department of Transportation (IDOT) selected Benesch to conduct preliminary design evaluations of the corridor’s existing conditions in Peoria, IL. This exploration revealed this 11-mile segment of I-74 had become incapable of providing the quality of traffic service expected of interstate highways. Ramps were too sharp, grades too steep, merging distances too short and clearances inadequate, resulting in accident rates in many areas that exceeded statewide averages by a factor of 10.
IDOT retained Benesch to provide final design services, in addition to consultant management activities. Together with IDOT, Benesch established a vision for the overall project and planned the route to its successful completion. Effective coordination with seven design consultants and the management of the overall budget were crucial to that success.
The design scope of work included: preparation of construction documents for nine complex structures (including curved steel girder bridges, tunnels, PPC bulb-T bridges, an arched pier bridge and the shortening of the Murray Baker Bridge cantilevered truss); the corridor-wide high mast, arterial street, under bridge and tunnel lighting; highway and arterial signage; and landscaping. Other highlights include precast and cast-in-place concrete arched pier bridges that resulted in substantial cost savings, as well as elliptical bridge bollards and reflective roadway signs.