Living in NJ and traveling up to Maine, we did get routed onto the Sawmill River Parkway once by MapQuest -- long before we had our Garmin Nuvi that was the only way we had to plan our trips other than paper maps. That was a harrowing experience driving a 27' motorhome -- we missed the sign that said "cars only" as an 18 wheeler decided to burn past us on the right just as we passed the sign. Beautiful arched stone bridges began appearing and the only way thru was dead center between both lanes. Oh the gestures and horns I elicited from passing motorists as I would glide back right after each underpass. Yes, there are parkways to stay off of in New York state! I do not know what other roads there are limited to passenger cars only, but definitely avoid this one! To get around it, we would always drive up Rt 287 in NJ to 87 and then cut over once we were far enough north. I hate traffic, can you tell?