I think it's to keep the citizens from leaving the state. If all you've got is 200 miles range in your EV, it's hard to leave a state that large. You'd have to stop and recharge your scooter/car. If they can't leave, they've still got a tax base, sorta.
It should make for some interesting times when the battery gives out halfway between Barstow and Needles heading east on I-40 and it's 120 degrees outside.
