Looking for smoothest way around NYC from RI to MD

X2 on what esyers said.

The "low" bridges on the parkway are arched and only low on the shoulders. They are well signed.

The Tappan Zee is toll free in the direction you are going. If you want to avoid the Parkway tolls, you can take I287 to join with the Turnpike. It's a few miles longer though. Avoid the rush hours on either the Parkway or I287, traffic can be awful.

Vehicles with propane, including RVs, are forbidden from the tunnel on I95 in Baltimore. You need to go around on I695.