Neither google maps nor my GPS told me before the fact that Holloway Mountain Road down to Banner Elk is a dirt road. This feature is supposed to be included in bing maps but even that failed for this particular road.

Anybody got a good way?

I have yet to find a really good way to do this. I'll be watching this thread.

Well, if you notice a lot of dust, ruts, or mud, good chance it's dirt.  The bike doesn't handle as well.  You can pretty much tell if you are on asphalt or concrete.  At least, I can.  The bike gets more dirty on dirt roads...  This really is no mystery to the savvy rider of course, but even they can be fooled if not paying attention.

On the sauce again, Jim? 

I'm not sure how GPS works but in all seriousness, all you need to do is get a good old fashioned paper map from your local store and roads are marked paved or dirt, at least the roads on the map are, small, county or township roads may not be on the map depending on how big the state is and how much info they can get onto the paper without the print being too small. You may also want to look into something called a "gazetteer" check the spelling, that breaks a state into grids and show EVERY single road in the state, paved or dirt. Good luck, I recently got lost in rural Ohio Holmes county on the tertiary roads that were basically kinda paved 1 1/2 lane buggy trails, when I got home, all of them were marked on my Gazetteer.

DeLorme maps is yer friend.

For small roads away from major highways, I like my GreenTrails maps.  Mostly aimed at hikers, etc., but they show all road types, elevation contours, etc.

On the sauce again, Jim? 

Of course.

The only way I know of is to use Google Earth's Street View. Drag the little man icon onto the road you're interested in and see if it looks to be paved. Unfortunately, just because one area looks to be paved, of course that doesn't mean the entire road is 

jeebus....
google maps....
and pic satellite view.... and zoom in...
wow... that was easy.
I can even do it on my phone.

The only way I know of is to use Google Earth's Street View. Drag the little man icon onto the road you're interested in and see if it looks to be paved. Unfortunately, just because one area looks to be paved, of course that doesn't mean the entire road is 

Yep, what he ↑ said. If the road doesn't highlight in blue when you bring the little man icon near it then 90% chance it's not paved. Get the street view at the ends of the road in question and inspect from the paved ends. Google doesn't street-view every paved road, but the majority of them are. They usually don't street view gravel/dirt roads but there are exceptions such as the Dalton Hwy in AK. Sometimes Base Camp will not let you use a road no matter how you try to make it do so, it will run you to a certain point and then U-turn you back another way, this usually means an unpaved section. 

I'm not sure that I have the correct road, but applying the Google Map Satellite view inspection technique to Hwy 1559 going north from the intersection of Hwy 221 in NC, I can see that it starts off as paved. From the satellite view I can see a painted center stripe going as far as the Blue Ridge Parkway exit, then none after that so I assume it is unpaved from there north until the intersection with Church Hollow Road.

If I am not on the right bike, my rule is "no yellow lines" find another route.  Sometimes that does bite me though because the county line is crossed and the road deteriorates. 

We've got plenty of good paved roads here in Virginia without lines of any sort...

We've got plenty of good paved roads here in Virginia without lines of any sort...

  I was on some of those last week between Hillsville and the Cumberland Gap.  They were good roads, but the problem was that the cagers coming towards me thought they were one way roads and I was going the wrong way!

Yeah, I know what  you are saying.  I usually keep to the right cresting hills and short sight distances.  I've been doing that for years so it's second nature to me.

Once upon a time, I was transferred from San Diego to San Francisco and thought it might be fun to take an easy, scenic cruise up the coast highway, picking it up somewhere North of L.A.  I knew I had erred when it occurred to me that I was riding 2.5 miles for every mile of progress North, but I finally had to throw in the towel when it turned into a dirt road.  Somewhere I took a right, went up a short mountain and then turned the engine off and coasted down the other side for about 10 miles.

I like dirt roads.  I think a Versys 1000 may be my next bike.