Boston to Acadia, Maine

I95 in Maine (up to Gardiner) is the Maine Turnpike with tolls (total cost around $12-16 for 5 axles, IIRC). 295 will be cheaper.

Depending on time of day, if you need to avoid Portland traffic you can stay on 95 (rather than take 295 in the Portland area) to the Yarmouth spur over to 295 and avoid some of the toll cost.

Route 1 will be stop and go with traffic lights through small towns, but shouldn't be a problem for the coach. Faster route is to go up to Bangor then 395 to 1A.

I've gone up through Maine from here (just outside Boston) more times than I can count. Just as an aside, calling Route 1 a "coastal" route is a bit of a stretch-there are very few water views. I find it way too slow for my liking. You will hit tolls on 95 but it's a smooth sail up to Bangor and as mck stated taking 395 to 1A is much faster. 295 isn't bad, but it does go through the city-if you can avoid it at rush hour and during peak travel times on Saturday a.m. and Sunday p.m. you'll be better off. 295 does, however, offer some really cool views of the water around the city. Either way you'll have no problems with the size of the vehicle. I'd check to see if there's construction on either route, which may be a deciding factor.

Just made trek from Portland to Camden onto Acadia. Very nice rte. and enjoyed scenery. Should have no issues with bridges. Enjoy