The Blink Network just posted a PDF with sample notices an EV driver can put on electric cars that are blocking access to a charging station :- https://www.blinknetwork.com/drivingelectric
Like:
The idea is nice and as I wrote up in a news article, it is important to educate the gas car drivers. It can be tempting to turn into the Hulk and smash things, but ... What's more likely, that the gas car driver has no idea what charging stations are for, or that the gas car driver is being purposely rude?
Electric car charging station etiquette is very important to work out.
