What's this 67th street ramp you are referring to? I ride my bike down the Eastside greenway to work a lot and there is no ramp there. They are doing construction south of 62nd on the greenway but I am not sure that even when it is complete that there would be an exit farther south than the 62nd street ramp.

Also the bike path on East 90th Street has been painted on (no cool green color though) and the street has been re-paved this summer. Makes for a much nicer ride back from Central Park.