To replace the deteriorating Sixth Street viaduct, Milwaukee wanted a bridge that would be a signature for the city as well as a stimulus for the development of the Menomonee River Valley and a gateway to the thriving community on the city’s near south side. They also wanted to get the project designed and built in 24 months with only a 15-month traffic disruption.
After considering several options, the planners decided on a pair of cable-stayed bridges to give the look they were aiming for and to deliver traffic to a pair of at-grade double-leaf bascule bridges in the valley. As the method for delivering the bridge complex on schedule, they chose design-build. Sixth Street is the first publicly funded road construction project in Wisconsin to use design-build.
The city of Milwaukee was the major proponent of design-build for the Sixth Street viaduct: "The design itself is unique. The cost is large. And the timetable upon which we had to construct it is very tight," Mariano Schifalacqua, Milwaukee’s commissioner of public works, told ROADS&BRIDGES. "So we felt that this was one of those projects that really lent itself to design-build."
"If this was standard DOT, this would be a two-year construction project, which is about what we have to do it," said Scott Piefer, P.E., vice president of Zenith Tech Inc., Waukesha, Wis. "So from a construction standpoint, I’m not sure we’re actually delivering the project any faster, but when you add in real estate, utility relocation and the design, and you’re doing all of that in two years, conservatively we’re cutting out a year and I wouldn’t doubt at all that we’re cutting out closer to two years from project conception to ribbon cutting."
HNTB Corp. developed the design for the bridges out of its Milwaukee office but with some of the work being done at its offices in New York and New Jersey. Zenith Tech is constructing the bascule bridges. Lunda Construction Co., Black River Falls, Wis., is constructing the cable-stayed bridges.
The owners group includes the Wisconsin DOT, the city of Milwaukee and Milwaukee County.
For more on the story, read the November issue of ROADS&BRIDGES magazine.