What to Know Starting Monday there is going to be one less bridge across the Schuylkill River between University City and Center City.

The 62-year-old Chestnut Street Bridge will close Aug. 5 for repairs that are expected to take until summer 2020 to complete.

The detours are different if you are biking, walking, riding the bus or driving.

Say goodbye -- for about a year -- to one of the links between University City and Center City Philadelphia.

The Chestnut Street bridge closed Monday night to vehicles and bikes. PennDOT will then begin a process to fix structurally-deficient bridge elements.

The reconstruction of the bridge built in 1957 is expected to last about a year.

"They are going to have a much improved bridge afterwards that is much safer for people to travel across," PennDOT Secretary Leslie Richards said.

Here's what you need to know:

How Long Will the Chestnut Street Bridge Close?

The the 62-year-old Chestnut Street Bridge closure began the night of Monday, Aug. 5. Construction is expected to last through most of next summer.

The roughly 1/3-mile span will be closed to vehicles and bikes from Schuylkill Avenue (adjacent to the IRS building) on the west side of the river to 23rd Street on the east side, PennDOT spokesman Brad Rudolph told NBC10.

About 19,000 vehicles cross the bridge every day, according to PennDOT. Thousands of more commuters from around the region use University City roads and bridges.

PennDOT

Which Bridges Can You Use During the Closure?

During the closure drivers should expect increased traffic on the Market Street and South Street bridges, the only two eastbound spans in the area available to cyclists and drivers.

Drivers will be detoured off Chestnut Street at 38th, 36th or 33rd Street to access Market Street to cross the river, Richards said.

Cyclists are urged to use 38th or 34th streets to access Spruce Street to the South Street Bridge, PennDOT says.

Pedestrians will also be detoured, needing to use the adjacent Market or Walnut street bridges during the closure.

Cars will be able to go westbound -- against the normal flow of traffic -- to access the 2400 Chestnut condos and parking garage, PennDOT said.

Chestnut Street access to the Schuylkill River Trail will not be available during the closure.

What About SEPTA Bus Service?

Two SEPTA routes, the 21 and 42 buses, will be detoured starting at 7 p.m. Monday until August 2020, the agency said Friday.

Route 21 buses will turn left from Chestnut Street onto 33rd Street, right on Market Street, continue across the river and then turn right onto 23rd Street before turning left onto Chestnut to continue on the normal route. The Route 21 eastbound stop at 33rd and Chestnut will be discontinued throughout the closure.

The Route 42 bus will go east on 33rd Street, make a right on Market Street, cross the river, turn right on 23rd Street and left on Chestnut Street before continuing on its normal route.

It's All Part of a $104M Reconstruction Plan

The yearlong closure is part of the nearly $104-million Chestnut Street Bridges project that PennDOT contracted Buckley & Company, Inc. to complete between August 2017 and late 2020.

PennDOT has laid out the work that will be done as crews will “remove and replace deck and repair the steel superstructure of the Chestnut Street Bridge over the Schuylkill River and Schuylkill Trail.”

Crews will also widen the sidewalks on the bridge and strengthen structurally deficient, weight-posted Chestnut Street masonry arch bridge structure over CSX rail tracks.

Officials with PennDOT call it a “completely renovation” of the structure that needs to be done every 50 to 100 years.