"Basically, a ramp / bridge"
There's not much to say about the Ped crossing other than it's a way across FDR by foot. FDR is an incredibly busy, highway of a street so you can't get across it safely by foot. So this bridge sort of crossing makes it easy to get from the East River bank over to the park and into the rest of Manhattan without getting run over by the whizzing cars of FDR. It's not exactly a scenic walk because of all the traffic noise, but if you need to get to the water, it's a good thing this is here. You can't live here, obviously. It's just for walking convenience.