The Union Pacific Railroad (UP) and STH 100 Bridges Project was part of the Zoo Interchange Reconstruction, an FHWA Mega Project. Opened to traffic in 1963, the Zoo Interchange is the connection between I-94, I-894, and US 45 in western Milwaukee County near the Milwaukee County Zoo.
The Zoo Interchange is one of Wisconsin’s oldest interstate interchanges and is currently the busiest interchange in the state. It plays a key role for commuters, retail customers, health care patients, freight, and other movements to major commercial and institutional sites.
This $73.3 million project entailed the construction of two new STH 100 bridges and one new bridge for UP, all over I-94. The completed bridges are twice as long as the original structures to accommodate the freeway widening underneath. Additional ramp structures and bridges over the Hank Aaron State Trail (HAST) were also included.
Construction included six retaining walls, three sign structures, and adjacent roadway and utility work. The project included removal and replacement of the current STH 100 bridges and construction of a new UP bridge over I-94 west of the current bridge. The original rail bridge remained open to train traffic during construction until the new bridge and re-aligned tracks were complete.
The Collins team provided construction inspection; electronic documentation; material testing/sampling; coordination with local, state, and utility agencies; cost and schedule tracking; contractor payment; and redesign of facilities for changed field conditions. The Collins team also developed document and cost control procedures that have been implemented statewide as best practices for construction management. Collins also led weekly and special contractor meetings and ensured quality control.