CENTER CITY (WPVI) --It began in April of 2015 and won't be done until at least another three years.
It's a huge and complex road and bridge restoration project on the bridges over the Vine Street Expressway.
The project is kind of a balancing act - everyday keep 11,000 Ben Franklin Parkway drivers moving as seven bridges that span 676 are replaced.
It means temporary traffic patterns with tight turns, which are tough on a bicycle.
"I've been pushed into the wall a couple times, especially at night, coming back at rush hour," bicyclist Daniel Murphy of Center City.
It's also tough if you are a pedestrian with a grandchild.
"[At one] particular signal you have to just run, you don't know how many times I have to run with the stroller," Phiroza Modi of Center City said.
On Wednesday, workers are due to begin pouring concrete onto a newly complete steel deck across from the main library. By mid-summer this will be a new key element for the biggest of the seven bridges and prompt a slight shift in the 20th Street traffic pattern.
Currently traffic on 20th breaks ever so slightly to the left around the work zone. Come mid-summer, that traffic will move ever so slightly to the right, over the new portion of the bridge, and the current traffic lanes will become the new work zone.
PennDOT's construction manager George Dunheimer told Action News, "We need to get the new bridge completed to a point where we can shift traffic over to the new bridge so we can demolish and do the rest of 20th Street."
20th Street pedestrians will not see a shift for now.
This $65 million project is on time, but with two stages and 15 phases of construction it's not slated to be done until 2019.