This is a fantastic site - a great way of visualising coverage!
A feature request - is it possible to detect travel routes marked as "ferry" and not include the kilometres in the range calculation?
As an example:
The red line at the bottom is a ferry route, but obviously vehicles do not use any battery while sitting still on the ferry. The line should extend all the way to Tasmania and cover about half the island.
I know this is a pretty specific request but if it is a generic "fix" it will probably apply in other locations as well, and the site is pretty damn awesome so there isn't much else to ask for!
I notice you use OpenStreetMap data - the relevant tag appears to be tag:route=ferry;motor_vehicle=yes.