EERE: Alternative Fuels Data Center Home Page Posts map; click on links get addresses for charging stations. If you enter route is counts stations available en route. Robecology
So, I went there but was underwhelmed. Plugshare has an ok trip planner that shows your route and all chargers within a selectable distance from the route. Hopefully when they join forces with recargo, the trip planner will make it into their map (and get enhanced with things like segments and distance ranges)