I have a Garmin Nuvi 260. Penny, probably similar to yours, it's not perfect, but does help. I'm in NJ, and to make things confusing, there are two roadways for the NJ Turnpike between interchanges 8A and 14, marked as "Cars, Trucks, and Buses" and "Cars Only." I always go "Cars Only" but the GPS tries to take me onto the "Truck Lanes" as they're called back here. If and when it realizes I'm in the car lanes, it will recalculate.
I'm always hesitant to take the way they say to go to Atlantic City, as I don't know the roads and how crowded they may be. I always go the freeway route, which is longer in mileage, but fewer lights. Last time down there I had my GPS, and as I was driving down 295, it suddenly knocked off 10 minutes of travel time because of the way I was going. There is a way that you can program it for the "Fastest Route" as opposed to the "Shortest Route."
2007 - Majesty of the Seas (Bahamas)
2009 - Enchantment of the Seas (Western Caribbean)
2010 - Freedom of the Seas (Western Caribbean)
2013 - Golden Princess (Alaska, roundtrip from Seattle)