| After more than 60 years in service, the aging superstructure of a 90-ft-long bridge that carried Interstate 476 over State Route 309 near Allentown, Pa., had reached the end of its life. The Pennsylvania Turnpike Commission selected an accelerated bridge construction (ABC) delivery method to ensure a swift replacement for a bridge that would carry roughly 30,000 vehicles per day. By using an accelerated method, the team determined that a new bridge could be installed within a 55-hour window over the weekend of Sept. 6-9, 2019. During that window, I-476 and SR 309 would be closed. The project marked the third time the PTC had closed the turnpike to use ABC techniques for bridge replacement. |
