The fact that Wisconsin’s oldest and busiest freeway interchange is called the Zoo, well, don’t let that scare you.
After resolving a perfect storm of design deficiencies, this confluence of highways – so named for its proximity to Milwaukee County Zoo – is now reconfigured for safety, functionality, multimodality and aesthetic appeal.
Zoo Core and Adjacent Arterials Interchange, in Milwaukee, has been honored by ASCE as a 2020 Outstanding Civil Engineering Achievement Honor Award recipient.
All 10 Honor Award projects will be showcased at ASCE’s 2020 OPAL Gala, March 13, in Washington, D.C., with two runners-up and the OCEA winner announced at the event.
By the time they were replacing, ad hoc, several bridge sections so depreciated that repairs no longer could be postponed, plans for a full-scale, systemic overhaul were well underway. Interstate 94, I-894 and U.S. 45 would need to achieve a different weave, and the megaproject of 2013-2018 was the largest public works project taken on by the state.
It included a four-level core interchange, nine miles of freeways, four miles of local roadway reconstruction, and five service interchanges to adjacent arterial economic corridors, where many of the 90,000 jobs within two miles of the Interchange are located. Forward 45, Wisconsin Construction Partners and multiple contractors partnered with WisDOT, FHWA, and the public to produce a state-of-the-art interstate reconfiguration that was completed on time and under budget.
Originally completed in 1963, the Zoo Interchange was deteriorated and could no longer safely accommodate 350,000 vehicles per day. An outdated design meant closely spaced left- and right-hand entrance and exit ramps, contributing to crash rates well higher than the statewide average. Critical to success was designing a plan that maintained access to the Milwaukee Regional Medical Center (MRMC), which serves as the region’s only Level 1 trauma center and includes nationally recognized Children’s Hospital of Wisconsin, Froedtert Hospital, and the Medical College of Wisconsin.
Through innovative design and outreach efforts, the team minimized construction impacts on neighborhoods and businesses. Early analysis shows the new Interchange is exhibiting operations benefits and resulting in significant improvements to traffic safety and system users’ well-being. The contractors met all major interim schedule milestones, building public trust, and businesses like the County Zoo, MRMC and State Fair Park remained open. The Pettit National Ice Center even held the U.S. Olympic speedskating trials without disruption.
Freeway volume during the postconstruction period increased; however, the additional capacity created can carry higher traffic volumes during peak periods. Travel times have improved by 7 percent and freeway crashes have decreased by approximately 35 percent. Arterial roadway crashes are 18% fewer.
Traffic management was addressed early in design to ensure mobility and access during the multiple construction contracts sequenced by the team. No longer a “malfunction junction,” this is one highway complex that will do its job for many years to come.
It has left stakeholders with a sense of pride. Colorful, textural murals showcasing notable area attractions were cast into the retaining walls, and decorative silhouettes adorn bridge fencing. The animals are there, you can bet.