On Wednesday, the Mulberry Street bridge in Harrisburg will close until late December.
The bridge is more than 100-years-old and is in need of repair.
The bridge will be closed to the pedestrians and about 12,000 cars that travel on it everyday.
PennDOT officials said once the work is completed, the bridge will look better and it will be safer.
The $17 million project calls for increased lighting, a bike lane and overall safety improvements for pedestrians.
The murals on the bridge will be saved. Sponsors plan to relocate them to city playgrounds.
CAT has already started a new bus line to help people get into the city.
Crews will work on the bridge for 10 hours a day, six days a week to get the job done.
The bridge should reopen to traffic in late December, but the overall project will take two years.