The gas tax is what pays for the upkeep of roads in the United States. Granted, it doesn't pay nearly enough to actually keep the roads in good condition, just working condition. Electric car owners use to roads but pay no gas tax, so the state of Washington has decided that registering an electric car should cost $100 more than registering a gas-powered car. 

It's ironic that the state gives EV buyers a tax credit, and then taxes them extra, but it makes sense in a weird way.

Related: Gallery: 10 Cool Electric Cars

[via Hybrid Cars]