Most property adjacent to railroad tracks/expressways is zoned "commercial". You'd have to be a pretty dim bulb to build a home next to existing tracks or expressways, so the property is probably cheap, especially in a town.
Anvil CG in Williamsburg is so close that you could slap hands with the conductor without ever getting up from your chair. Both KOAs and American Heritage are close enough to hear the trains, and they pass by fairly often. They're all headed to Hampton Roads, the largest sheltered deep water port on the east coast, surrounded by Norfolk, Newport News and Hampton.
BTW, if you time it just right, when you drive thru the underwater tunnel between Hampton and Norfolk, you can get run over by an aircraft carrier. :)