Electrified rails on trains have been around much longer than parking stations. Plus batteries are the biggest problem (and most expensive) part of ecars, so this is a good idea to try out.
It's basically a scaled up version of a slot car track.
Did you read the article? This is addressed.
Note how industrial power is hardly ever ground fault protected because the leakage currents in the standard setup are too high already to reliably detect a ground fault.
In other words: if the system delivers enough power to electrical cars to meaningfully affect their state of charge there is inherent danger.
It clearly states that salt water in the rail only gives off 1 volt at road level and that you can walk on it barefoot.