I too agree that Parking at NY piers can be very convenient since you park right next to ships and it is generally just an escalator ride down to get into terminal and board. However I will offer some comment about changes in recent years brought about by the mere number of ships sailing from NY. If you are sailing or returning on a date that several ships are in port it can be a bit of a mess. Even on those dates I would probably still say that parking at the pier is still the most convenient but one should be prepared for a huge traffic jam.
The pier entrance is immediately at the bottom of ramp exiting from the end of the Westside Hwy ( Henry Hudson Pky ) at around 55th street. As you come done ramp to street level the pier entrance ramp is to your right and can't miss it. The problem that arise is that the pier area is like an airport arrival/departure area, a long two lane road one way where you stop and drop or pickup at the pier entrance for you ship. If only one ship or two moderate size ships are in not bad but if several ships or a couple of large ships are in it can become one barely moving mess. Since there is no place that you will be allowed to stop unless you are droppng or unless you are picking up the person AND they are already standing there ( you will not be allowed to stop there for more than a minute or two ) the congestion can really mess you up as going around and back again is not easy in NY traffic. You might want to check the port time table for the dates involved. You can do that on the worldshipny DOT com website.
That said, driving and parking there still the most convenient since anyone picking you up faces the same challenge if the port arrival day is one with a lot of ship traffic. What people do is make arrangements to make contact by cellphone so that pick up vehicle doesn't get into traffic line until you are already out there with your luggage.
This has been somewhat heloed by Royal Caribbean and Celebrity sailing from bayonne Nj I would presume since my last sailing from NY but you should still be aware of it.
I long for the days when one ship sailed Saturday and one Sunday as far as parking is concerned. used to be able to pull up, drop luggage, go to end and up to parking level and be onboard sucking down the first drink in no time flat. Same leaving, but last time took me an hour to get off parking deck and pick up wife. Parking deck ramp also feeds into this two lane pick up and drop off area.
Cost wise is was $180 max but you should call phone number and verify what this years rates are. Still by NY standards ( not too many others ) parking is a bargain.
George in NY