Work on a long-anticipated replacement of the 101-year-old Koppel bridge will begin today. Drivers using the bridge will be subject to lane restrictions to accommodate work crews clearing trees and access roads. The estimated cost of the project is $27.58 million. PennDot officials said the new bridge is expected to be open by the end of 2018, but work at the site is expected to continue until early June 2019. The existing bridge, which carries Route 351 over the Beaver River between Koppel and North Sewickley Township, was built in 1915.