When the bridge was built in 1912, it was the largest of its type in the world. General Trexler and his Portland Cement Company built the bridge to connect the trolley service from center city Allentown to points south, all the way to Philadelphia. Trexler was also a principal in the trolley company. PennDOT is now doing the first major renovation to the bridge in a century, and I am sorry to report it seems very compromised. While the shorter approaches from both ends are being completely replaced, the longer middle section remains. It appears as if they choose to replace those sections because they're not as high off the ground. The broken rubble from those sections, which could be examined last year on Harrison Street, showed dense concrete, in excellent shape. The bridge in 1912 was a showcase for the new Lehigh Portland Cement Company, and the pride of both Allentown and Trexler. If the high middle sections are still structurally sound, I suspect the approaches were also. I've been told by sources that PennDOT is having trouble with binding the new roadbed to the old concrete. In addition to the binding issue, the new roadbed is higher, adding additional weight to the high arches. Lastly, the bridge to being altered architecturally, by removing the signature walls. This change is supposed to accommodate new walls designed for suicide prevention. I would think that a barrier could have been designed and fastened to the classic existing walls.