Hennepin County will shut down sections of Portland and Cedar avenues on Monday to demolish the century-old bridges on those streets that cross the Midtown Greenway, bridges that county officials say are beyond repair.
In their places, new bridges resembling the neoclassical revival design of the originals will be built this summer.
The county also will widen the sidewalk on the bridge decks, change traffic lanes and add a buffer to the Portland Avenue bike lane as part of the reconstruction.
It will cost about $4 million to rebuild each bridge, about the same amount as rehabbing each of them. The new bridges are expected to last 75 to 100 years.
Both Portland and Cedar avenues will be closed to traffic between 28th and Lake streets through December, when they are scheduled to reopen with the new bridges.
Between them, the two avenues carry more than 24,000 vehicles a day which will be rerouted.
Bicyclists and pedestrians on the Greenway trail below the bridges will also need to be temporarily rerouted. The trail below Cedar Avenue will close May 15 for several days and reopen after crews finish demolishing the bridge. The trail below Portland Avenue is expected to close May 22 for the demolition of that bridge.
The Portland bridge was built in 1914-15, and the Cedar bridge a year later. Of the 38 bridges that cross the 2.8-mile historic Midtown corridor district, 26 original bridges remain that were built from 1912 to 1916.
For information about detours and the projects, go to hennepin.us/greenwaybridges/.