Recently a graduate student at NC State University published a set of interactive dialect maps based on data from a dialect survey by Bert Vaux (University of Cambridge).
Dialect maps by Joshua Katz based on data from the 122-question survey conducted by Bert Vaux, Department of Linguistics, University of Cambridge. The web interface was coded with Shiny and deployed using the hosting service provided by RStudio. These maps are preliminary results only—more complete/correct versions are in development.
via Dialect Survey Maps.