For pedestrians and bicyclists in Minneapolis, getting around will be a bit more inconvenient as three bridge repair and trail improvement projects create detours for months.

A fourth project will also force those who walk or roll to take the long way around, but that one will last only for a month.

Work begins April 7 on rehabilitating Bridge No. 9 over the Mississippi River, a key connection along the Dinkytown Greenway linking the University of Minnesota's East Bank with the West Bank and west end of downtown.

For the next eight months — yes, until December — the 1,450 bicyclists and 540 pedestrians who use the century-old bridge on average each day will be forced to find another river crossing. The nearest is the 10th Avenue Bridge, next to I-35W.

Minneapolis took over the former Northern Pacific Railroad Bridge in 1986 and turned it into a bike and pedestrian crossing in 1999. This year, the city is spending $6.1 million to replace the bridge deck and abutments on both ends of the bridge. The work comes after the city spent the past four summers shoring up deteriorating piers and substructure.

Project manager and engineer Oscar Weber said the city is investing in the historic bridge to "provide safe and reliable infrastructure for anybody spending time in Minneapolis." With the city prioritizing active transportation, he hopes the repair project will "encourage people to explore using bikes or their feet to get between places."

Crumbling piers are being repaired as part of the Bridge No. 9 restoration project.

Not far away, the Minneapolis Parks and Recreation Board will build a tunnel under Plymouth Avenue/8th Avenue NE. to make it safer for cyclists and walkers get between Boom Island and the new Graco Park, said Minneapolis Parks and Recreation spokesman Ben Johnson.

To do that, the Plymouth Avenue Bridge will close starting April 21, taking away option for motorists and anybody else needing to cross the Mississippi River there.

"Stick with us for four months, because we will have beautiful amenities for generations to come," Johnson said.

Over the summer, crews will dig down 20 feet and put in a 24-foot-wide tunnel to allow trail users to bypass an unsafe crossing at Sibley Street, Johnson said.

When complete, around Aug. 22, the project will give cyclists and walkers a 2-mile uninterrupted trail along the Mississippi River from Sheridan Memorial Park to Nicollet Island.

The Park Board will maintain the at-grade crossing at Sibley Street on the east end of the bridge. The board will put in flashers and install bump-outs to make the "not safe or fun intersection" better for those who use the crosswalk, Johnson said.

For the second straight year, the Stone Arch Bridge will remain closed as MnDOT completes restoration of the landmark structure linking downtown with the St. Anthony Main area. The $38 million project to replace worn stone and replace mortar is expected to be largely complete by fall, but means another river crossing out of commission.

A fourth project in south Minneapolis will make it tougher for those who walk or roll to get from one side of I-94 to the other. The Hiawatha LRT trail will be closed Monday through May 2 between 15th Avenue S. and E. Franklin Avenue. The closure is related to MnDOT's bridge repair project on the freeway.