'Travel provision' in ZEV rules means EV limited outside CA

The subject may be plug-in automotive sales, but the better metaphor for how California is monopolizing them comes from to sailing. It's a tailwind. Residents of the most populous US state have by far the most access to a wider array of plug-in hybrids and battery-electric vehicles because of a wrinkle in the law that sets the automotive credits for zero-emissions vehicles (ZEV). And that California law clearly favors the Golden State, according to Green Car Reports.

See, the ZEV credits that automakers earn for selling a vehicle in one state get applied to all states with ZEV provisions. The upshot of this so-called "travel provision" is that an automaker that wants to simplify things like distribution strategy and promotional costs will naturally gravitate towards California because that's likely where it's easiest to generate the most sales.

The upshot, of course, is that Californians have access to more than 20 plug-in vehicle models, while Northeastern states with similar ZEV provisions, including Connecticut, Maine, Maryland, and New York, can generally only choose from the BMW i3, Tesla Model S and, of course, the Nissan Leaf. Those ZEV-credit laws are slated to change in 2017 in a manner that will likely balance things out a bit.