I stumbled upon the following FAQ from the federal Manual on Uniform Traffic Control Devices' website: Q: What are the approved uses of green-colored pavement? A: Green-colored pavement is only approved for use in bicycle lanes in accordance with Interim Approval 14, and is not approved for general use in any bicycle facility. Use of green-colored pavement for other bicycle facilities other than bicycle lanes may be used only with FHWA granting experimentation approval under the provisions of Section 1A.10. More information is provided here. Agencies sometimes use green-colored pavement to supplement, fill in, or outline parking areas or parking stalls for electric vehicle charging stations in order to express the agency's commitment to environmentally friendly initiatives. This practice is not in compliance with Interim Approval 14 and the FHWA is not considering this alternative use of green-colored pavement for experimentation. Although the applicability of the MUTCD may be limited in certain settings involving parking stalls, agencies are encouraged to adhere to the MUTCD with respect to disallowing green-colored pavement in parking facilities for the purpose of maintaining uniformity among similar facilities. So, it appears that painting a parking stall for the express purpose of BEV charging is frowned upon by the rule makers. Curses!