Originally Posted by Air
If you're already on the bike path that does change anything?
If you're going south on the 'Serpentine Promenade' you'll need to continue down to 79th street. Then you can use either the large staircase down to the usual underpass that leads out to the river's edge, or you can use the rotunda or 79th Street traffic circle toacess the bike path south of 79th Street.