A five-year, $82 million project to replace seven bridges over the Vine Street Expressway will also remodel the cultural spine of the city.

In time to celebrate the 100th anniversary in 2017 of the Benjamin Franklin Parkway and its museums, institutes, sculptures, and pocket parks, the rehab will aim to make the strip prettier and more functional.

The death-defying pedestrian crossing between the Free Library and the Franklin Institute will be improved. Winter Street will be realigned to reduce the traffic conflict with pedestrians.

A new patch of park will cover a piece of I-676 in front of the library. More than 10,000 shrubs and trees will be planted, while the statue of Venezuelan revolutionary Francisco de Miranda will be transplanted.

Sidewalks will replace dirt along Vine Street. More than 16,000 granite and brick pavers will give a new sheen to park areas. And 31 park benches will be added.

Construction is to start in February, but it will come to a screeching halt Aug. 31, to avoid interfering with the massive crowds expected for the September visit of Pope Francis and the World Meeting of Families.

"PennDot certainly was aware that this is the cultural boulevard through Philadelphia, and it couldn't be done as a pure highway project," said James Pezzotti, a senior engineer with Pennoni Associates, consulting with the Pennsylvania Department of Transportation on the project.

The massive project will be done in two stages, with all construction to be complete by Nov. 7, 2019.

The bridges to be replaced carry 18th, 19th, the Parkway/20th Street, 21st, and 22d Streets, as well as the pedestrian bridges in front of the library and the old Family Court building.

In the meantime, motorists will face nighttime closures of the expressway, local residents will endure construction noise and detours, and scores of homeless people will be displaced from a feeding zone in front of the former court building, when it becomes a staging area for contractors.

For all that is being done, one thing is not happening: The expressway will not be covered over.

PennDot decided it was too costly and difficult to cap the below-grade highway, much to the despair of those who see I-676 as an intrusive ditch that splits the cultural heart of the city.

"It would be awesome if this could be covered over instead of being a chasm through the city," said Kyle McShane, 27, of Haverford, the creator of a Cap 676 page on Facebook. "You could put parks or cafés or bike trails or better storm-water management there."

"It would be like the Big Dig in Boston, but we wouldn't even need to dig the tunnel, because it's already there."

"It all should be covered," said David Searles, an architect, who is president of the Logan Square Neighborhood Association. "There's no reason for it not to be, other than money."

PennDot considered putting a lid on the expressway as part of this project, said Charles H. Davies, the assistant district executive for design at PennDot's Southeastern Region.

"We did look into it fairly early on," Davies said. "It would be very disruptive, the cost would be significant, and we decided to concentrate on the incredible problem at hand - the bridges worsening quickly."

The one area that will be capped is a 5,625-square-foot wedge between 20th Street and Shakespeare Park in front of the library. The cap will be landscaped and added to the park.

Searles sees that park expansion as one of two significant benefits that local residents will get after enduring years of construction. The other will be the realignment of Winter Street near the Franklin Institute.

The street will be shifted to intersect with the Parkway before 20th Street, providing new space for greenery and pedestrians.

The driving force for the whole project was the need to replace the seven overpasses, Davies said.

The five vehicle bridges and two pedestrian bridges date to the 1950s and are falling apart, he said. The bridge that carries the Parkway and 20th Street over the expressway is in especially dire straits, with timbers now helping to shore it up.

The existing double-span bridges will be replaced with single-span bridges, eliminating the existing piers in the middle of the expressway.

"My understanding is it has to be done. I think everybody would be happy if it weren't happening," said Searles, "but we're trying to take it in stride."

Last week, Buckley & Co. Inc., of Philadelphia, was selected as the apparent low bidder to build the project for $64.8 million. PennDot spent an additional $17 million in design and engineering.

The construction timetable:

Stage One: February 2015-June 2017. Replacement of the Benjamin Franklin Parkway/20th Street, 19th Street and two pedestrian bridges, and realignment of Winter Street.

Stage Two: July 2017-November 2019. Replacement of the 22d, 21st, and 18th Street bridges.

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