Gonna take a while to develop that infrastructure. I'm not even sure it's worth it to go down that road. It quickly becomes apparent that charging is not going to win the day if you're spending 15-30 minutes at a gas station every 400 miles on a road trip. Gasoline engines take 5 minutes tops. Americans, by and large, have money for more expensive gas if they are taking road trips. What they don't have is an abundance of time.
The better option going forward would be to do what the Chinese have done. Just like you have an Exxon or Chevron credit card, you get an account with a company that supplies batteries for cars. When you need one, you pull in to the station. A robot from under your car takes out your depleted battery and puts it into a charger located under ground. Once it does that, it takes a charged battery and installs it. You're on your way. They have it down to 3 minutes in some cases. You never get out of your car.