I have to agree with Rick Hurst. Since he and I inspect in the same general area, we both see quite alot of these without a vapor barrier and it's dry as a bone under there.

I have recently done construction inspections on new home that had the cadalliac of all crawlspace vapor barriers and moisture control designs that I have been privy to examine. The vapor barriers were installed over gravel, The vapor barrier had nicely overlapping joints of 12", swales were cut into the sides under the home to direct water to the exterior downspout tie-in. Also, A set of two sump pumps were present as well as two mechanical vents.

Dry as a bone down there.

Rich