This project is a portion of the USH 41 six-lane project in Winnebago County. The 9th Avenue corridor consists of four intersections, Washburn Street, the southbound and northbound USH 41 ramp terminals and Koeller Street. The interchange was reconfigured as a tight diamond interchange. 9th Avenue has two through lanes in each direction. All four of the existing signalized intersections were designed as roundabouts.
OMNNI’s role in the project was to take the concept/preliminary layout of the 9th Avenue corridor as defined in the USH 41 Ramp Terminal Intersection Study Report and develop 60% plans and then final plans and specifications. Some of the design challenges besides the close proximity of the intersections are the vertical profile through the roundabouts and construction staging to allow access to Washburn Street and Koeller Street.