New Jersey's gas crunch in the wake of Hurricane Sandy has become so severe that state officials are implementing gas rationing for passenger vehicles in the counties hardest hit by the storm.

Gov. Chris Christie signed an executive order today announcing a state of energy emergency and instituting gas rationing for the purchase of fuel by motorists in 12 counties, starting Saturday at noon.

Calling the fuel supply in the state a "shortage" that could endanger public health, safety and welfare, the rationing will take place in Bergen, Essex, Hudson, Hunterdon, Middlesex, Morris, Monmouth, Passaic, Somerset, Sussex, Union and Warren counties.

"As New Jerseyans continue the long process of recovering from Hurricane Sandy, it's imperative that our families have secure, reliable access to essential supplies like fuel," said Christie in a statement issued just before 8 p.m. He cited the long lines and otherwise disorderly sales of fuel following Hurricane Sandy.

READ THE FULL EXECUTIVE ORDER HERE

According to the order, all retail gasoline dealers are required to sell fuel for use in a passenger vehicle according to the last number appearing on a vehicle's license plate.

Vehicles with license plates, the last number of which is an odd number, can fill up at stations in these counties only on odd-numbered days of the month, the order said.

Vehicles with license plates, the last number of which is an even number, can fill up only on even-numbered days.

Zero is considered an even number.

The order does not apply to the purchase of fuel by individuals with gas canisters. Walk-ups are still permitted.

All license plates not displaying a number, such as vanity plates, are considered odd, and should fill up on odd numbered days of the month, the order said.

The ration order will remain in effect for as long as the limited declared state of energy emergency is in effect.

"I encourage all New Jerseyans to abide by this system – motorists and retail dealers alike – to ease wait times and improve access for everyone," said Attorney General Jeffery S. Chiesa. "Those who choose to disregard this order will be prosecuted to the fullest extent permitted under the Governor’s state of emergency authority."

Related coverage:

• Belleville votes to ration gasoline after Hurricane Sandy



• Sandy update: Gas lines still hours long, more than 1M still without power

• Hurricane Sandy gas lines: Twitter updates from across N.J.

• Live gas blog: Hurricane Sandy causes massive lines at N.J. gas stations