Sorry I'm a little late with this reply and thank you Bobbi for confirming this information.
All of the port signage clearly states you can drop off / pick up passengers via private car at the port.
I'm going to repost a few photos plus add a couple to hopefully assist with anyone dropping off and picking up passengers:
It's a One -Way access to the ship terminal. You must approach from the 12th (9A) & 55th St intersection, where you'll see these signs.
You need to enter the viaduct ramp by following the sign marked "Private cars / All Parking / All taxis.
I didn't manage a photo of the sign at the top of the ramp in the distance, but if you zoom in - you'll see that it clearly states:
Passenger drop-off/pick-up with an arrow directing you to proceed straight ahead or Parking with an arrow to the right.
Also notice the lane arrows. Both lead to Level 2 but only the Right lane to level 3 parking.
At the top of the ramp, the road forks. (this is an old photo but it's a great one)
Current signage - again, only turn right if you are parking. you can see we're driving straight ahead on Level 2.
The "passenger pickup" area is the first sign you'll spot and is set the farthest away from the terminal entrance - behind the taxis.
If these cones are blocking the curb, just double park like our cab driver did.
Very easy!
for pick up times: Express walk-off was 7:30am.
We were later to disembark because we had the late seating for breakfast at 8:15 am (Animator's Palateand took our time. We were off the ship by 9.
Here is the official cruise information