Making Washington Avenue span safe for light rail will be costly.
It's a fracture-critical 1960s steel bridge over the Mississippi River, and last year parts of it were deemed too weak to hold up pedestrians. Why not put some 50-ton rail cars on it?
After months of silence about how this could be accomplished, engineers for the Central Corridor light-rail line on Wednesday presented a plan to spend $56 million to bring the Washington Avenue Bridge up to 21st-century safety standards -- and how they'll pay the larger-than-expected cost.
The unusual two-level bridge, which is painted maroon and gold and connects the two halves of the University of Minnesota's main campus, will have its main decks replaced, and four new trusses will run lengthwise to provide additional support. That will take the bridge off the list of those that are fracture critical, a term meaning that the failure of one piece could lead to the failure of the entire structure
All of the work "will really create, essentially, a new bridge," said Mark Fuhrmann, project director with the Metropolitan Council, which is building the line.
Work on the bridge is scheduled to start later next year. One lane of traffic in each direction will be open during construction, and when the rail line is complete, that's how many lanes will be open to motor traffic -- light rail tracks will take up what are now the inside lanes.
Each half of the pedestrian deck will be closed for a time during construction. Last year, sections of that deck were blocked off because of structural problems unrelated to the retrofitting of the lower deck. The entire pedestrian level reopened in the spring.
Earlier projections of the full bridge's overhaul were a little over $40 million, Fuhrmann said, noting that the new cost includes contingency funds. About $26 million for the rehab will come from state sources, while $30 million will be paid from the Central Corridor's $941 million budget. Half of that money is to come from the federal government.
Hennepin County Commissioner Peter McLaughlin said it's appropriate for the state to pay for rehab work on a bridge "that they transferred to us in that condition." That stretch of Washington Avenue used to be a state highway and is now a county road.
Furhmann said that, when the work is done, the county will have primary responsibility for the bridge, while the Met Council will maintain the track portion.
The bridge is just downriver from where the old 35W bridge plunged into the river in 2007, killing 13 people and injuring more than 100. That bridge, which opened in 1967, two years after the Washington Avenue Bridge, was also fracture critical.
The stronger deck, rehabbed piers and other changes will extend the Washington Avenue Bridge's useful life another 70 years, said Chuck Hymes, a project manager with AECOM, one of the firms consulting on the line.
Central Corridor trains are expected to start service in 2014, although full funding has not yet been approved by the Federal Transit Administration. Met Council Chairman Peter Bell repeatedly has warned that the project could be delayed if federal deadlines aren't met, and the FTA has expressed concerns over continued disagreements between the university and the council over how the line's vibrations and electromagnetic fields will affect research on campus.
The two parties met again Wednesday and reported more progress but no final deal.
Jim Foti • 612-673-4491