The closest airport to Newport, Rhode Island is TF Green airport in Providence, located about 40 minutes from the hotel. While Boston’s Logan Airport is further away – about 60 minutes – it has a greater variety of non stop flights available. For more details on Airports, transportation between the various airports and the hotel, and maps see:
Note that there is a $20.00 per day fee for parking at the hotel.
There is no shuttle service between the off site hotels and the Marriott.
The cost of a cab is about $9.00 each way. If you share a cab that might be reasonable. Howard Johnson's is right on the public bus route ($2.00 each way) you can get on in front of the hotel and ride it to the end (only 2 miles). It drops you at the gateway center right next to the Marriott. This may also be an option for the Residence Inn guests, check with the desk at registration for where to catch the bus.