Unlike most highway infrastructure, which was built after 1950, most (surviving) railroad infrastructure was built before 1950. Many exceptions in both directions, but generally that’s the case.
Which is a good thing because the facilities built prior to that date were generally overbuilt. This particular bridge was built in ’96.
It’s lasted over a century and still carries hundreds of Metro-North and Amtrak trains every day between New York’s Penn Station, New Haven, and Boston’s South Station.
Unfortunately, despite the overbuilding, this bridge is past its “best by” date and needs to be replaced. This week it’s been jamming when it moves, disrupting rail traffic on the entire Northeast Corridor. Near the end of the video, you can see a maintenance crew manually unbolting the movable part of the bridge prior to opening. The new structure, like the other movable bridges replaced on this line in the last 10 years, will probably not require a crew to open bridge.
By the way, WALK is the name Penn Central (successor to the original owner, the New York, New Haven, and Hartford RR) gave to the “interlocking” that controls the bridge and it’s approaches so that trains don’t run into the river. It’s located in Norwalk, Conn, and crosses the river of the same name.