A good part of the trip is on roads that are not super highway- speed limit 40 MPH or so.
The same thing applies from montauk to Fire Island. Also as I said traffic on LI and in the NYC area can be bad at times.
On weekends it can be just as bad or worse than during the week. I used hicksville because it's not far from where the ship leaves from and is basically in the center (north to south of the isl;and at that point).
All of this is of course an aproximation.
Dennis