making a trip in february got questions
Couple of ideas...
1. If you are concerned about restriced roads, you might want to buy the Rand McNally Motor Carrier's Road Atlas
http://www.randmcnally.com/rmc/company/cmpProducts.jsp?oid=-1073754318 .
2. To amplify on Gruffy's comment, I would suggest getting a label maker and putting a sign on your dash with your weight (lbs and tons), height, and possibly even length and width. If you think you'll ever be traveling to Canada and/or Mexico, this is a good time to calculate these values in metric units and list them as well.
3. Don't necessarily rely on Mapquest to route you, if you are concerned about side roads. As others have stated, sticking to major roads and interstates you should have no problems. So, also break out the paper maps, and see if you want to overrule all or part of the Mapquest suggested route.
4. Finally, since you seem to have narrowed your concern down to one particular part of your trip, you could also try contacting someone who regularly drives large vehicles in that area and find out if there are any concerns. Try talking to drivers or dispatchers with local trucking companies, earth moving contractors, etc. who regularly drive tall and heavy vehicles in that area and see if they have any problems. Unless you are talking about residential or gravel side roads, however, I seriously doubt that you'll see anything lower than 13'6" (normal max semi height), otherwise they'd perpertually be putting it back up after trucks knocked it down.