HACKENSACK, N.J. -In an effort to prevent a fuel shortage and ease waiting times at gas stations, New Jersey Gov. Chris Christie enacted odd-even gas rationing beginning at noon Saturday in Bergen, Passaic and 10 other northern New Jersey counties.

Motorists with license plates ending with an odd number can purchase gas only on an odd calendar day, while those whose plates end in an even number can go to the pump on even days under the executive order Christie signed on Friday night.

Other counties affected by the rationing are Morris, Hudson, Essex, Hunterdon, Middlesex, Monmouth, Somerset, Sussex, Union and Warren. Specialized plates or those not displaying a number will be considered odd-numbered plates. Customers walking to stations can fill their gas cans on any day.

"This system will ease the strain on those gas stations still operating while we work to bring more online for the public to access fuel, in a manner that is fair, easy to understand, and less stressful," Christie said in a statement.

Christie and state Attorney General Jeffrey Chiesa pledged strict enforcement of the restriction.

"Those who choose to disregard this order will be prosecuted to the fullest extent permitted under the governor's state of emergency authority," Chiesa said.

The order came as the gasoline crisis caused by Hurricane Sandy entered its fourth day with 80 percent of stations in northern New Jersey still closed because they had no fuel, no power or both.

On Friday, tensions flared at stations in every corner of Bergen and Passaic counties as motorists waited for hours in lines that stretched for miles. Fights erupted at several stations, including an alleged assault on a Fort Lee police officer by a disgruntled motorist in the pre-dawn hours. In Clifton, officers reported having to quell numerous disputes from angry customers. "The bottom line is, it's going to continue until the gas situation is over," Clifton Det. Sgt. Robert Bracken said.

Christie's order surprised Sal Risalvato, executive director of the New Jersey Gasoline C-Store Automotive Association, which represents 1,500 stations. "I don't think it's necessary, but there has to be something that quiets the storm," he said.

Before the order, fuel industry experts like Risalvato said that lines for gasoline should decrease significantly over the weekend as more stations are expected to regain power, but "any return to normalcy" at the pumps in North Jersey may last well into next week.

Hurricane Sandy knocked out the entire distribution system for gasoline in northern New Jersey, closed the port of New York and New Jersey, shut down the second-largest refinery on the East Coast and left hundreds of gas stations without power.

Christie said Friday that he wants power companies to restore electricity in areas where gas stations are closed. The state's largest gas station association is compiling a list of its 1,500 stations that have no power.

"We're going to go to PSE&G and JCP&L and say prioritize certain communities that have no gas station working," Christie said.

"The gas situation should be figured out in the next 24 to 48 hours," he said. "It's not just a supply issue, it is a power issue and we were not frankly, in the private sector, prepared for this widespread loss of power."

If the strategy works, "the total situation should ease by the end of the weekend," said Risalvato. "The pieces of the puzzle will start fitting together."

But, he added, "There's not going to be any return to normalcy at least through the end of next week."

It was unclear how power companies could follow Christie's suggestion. Because power is restored regionally not individually, gas stations can't get power back any faster than any other business or home, PSE&G executives said this week. The utility said power won't be restored systemwide until the end of next week.

Power companies were, however, able to get electricity to some key components of New Jersey's gas supply system by Friday.

A major pipeline that supplies New Jersey stations with fuel resumed pumping Friday morning after being knocked out of service by Sandy. The Colonial Pipeline has begun shipping gasoline to terminals, which are slowly coming back to life.

PSE&G restored power to the substations that serve two key distribution terminals in Linden. But while the Buckeye Partners terminal was pumping gas into tanker trucks by noon, the Phillips 66 terminal was only supplying emergency response vehicles with gas.

To get more fuel to desperate motorists, federal authorities on Friday temporarily waived regulations and will allow gasoline that doesn't meet the region's environmental standards for air emissions to be sold in New Jersey. Gas stations and their suppliers can accept shipments of conventional gasoline that is available in other regions of the country. They are normally required to sell reformulated gasoline that emits less smog-forming and toxic pollutants.

The federal government also waived a security regulation and will allow foreign-registered oil tankers to sail from the Gulf of Mexico to New York-area ports for a limited time.

Whether New Jersey will be able to process that oil into gasoline is at issue.

Phillips' massive Bayway Refinery remained shut down and could stay that way for weeks. The 238,000-barrels-per-day facility in Linden may be weeks away from restarting due to heavy damage caused by salt water flooding into the facility from the neighboring Arthur Kill during the storm, Reuters reported Friday. A Phillips spokesman would not comment on the report.

"There was some flooding in low-lying areas of the refinery," Greg Maxwell, chief financial officer and executive vice president of Phillips 66, said in an investor call Thursday, "but floodwaters have since receded. . . . We are currently assessing the condition of the assets and a decision on resuming the operations will be made once this assessment is complete."

Hess was one of the few chains to have almost all of its stations operating after the company arranged to have 85 generators installed before Sandy hit. The company opened and supplied 177 of 186 stations in New York City, Long Island and New Jersey.

Now, one legislator is calling for all gas stations to be equipped with generators so they can operate when the power is off. State Sen. Barbara Buono, D-Middlesex, said she would introduce legislation encouraging station owners to have backup power.

"With 'storms of the century' hitting New Jersey every October, it's clear that we need to take the same emergency precautions as hurricane-prone states like Florida," she said. Florida requires gas stations to have backup power sources, she said.

Still, no amount of electricity could help when gas supplies dwindled.

Cliff Spierer of Wyckoff said he had waited for six-and-a-half hours at a Hess station on Goffle Road in Ridgewood, only to learn that the station had run out of fuel a few hours earlier. The time of a future delivery was uncertain. But still he sat there. "Normally, I would never even consider doing this, because it's ridiculous, but at this point, I've invested the time," he said. "Call me crazy."

Police officers are now a common sight at gas stations. In Fort Lee, a man who was in line to get gas at a Route 1 Sunoco station was arrested Friday after he allegedly assaulted a police officer and had to be restrained by three officers. The confrontation began at 5:30 a.m. when Christian Cruz-Bello of East Elmhurst, N.Y., reached the front of the gas line, where an officer told him to wait because it was uncertain if the fuel had run out, police Chief Thomas Ripoli said.

Ripoli said Cruz-Bello ignored the warning and continued moving his car forward, but officers blocked him from entering the station. He became "enraged," the chief said, and walked to the pump with a gas can. He then allegedly struck Detective Nick Orta when he was told his car was blocking traffic and would be towed. Cruz-Bello was charged with aggravated assault on a police officer and resisting arrest.

In Wayne, the desperation has sparked several confrontations, including a woman arrested for threatening a person with a crowbar at a Sunoco station on Route 46 east. Each time a station gets a fuel delivery, Wayne must send two police officers to keep the peace, said Wayne Police Chief John Reardon.

Clifton police reported numerous fights at gas stations, including at least "four or five" that reportedly involved weapons, Detective Sgt. Robert Bracken said. One man was arrested at a city service station on Thursday.

"(There's) just major congestion and that's what causes a lot of the disputes. . . . The bottom line is, it's going to continue until the gas situation is over," Bracken said.

Wayne also reported fights at local gas stations, but no arrests.

Some drivers are blocking intersections and the entrances to businesses, and police have also dealt with spillover from stations in neighboring towns. Waiting lines at some places stretch half a mile to a mile, said Capt. James Clarke.

In Glen Rock, the line at the Exxon station on Maple and Rock Road are so lengthy that it wraps around Rock and through a commuter parking lot. Another Exxon station less than a mile away has traffic lined up through side streets.

"It's chaos," Police Chief Fred Stahman said. "People are brazenly cutting in line."

Karim Alfaoury, owner of the Lukoil gas station in Woodland Park, predicted that customers would be upset with the even-odd plan at first, but would adjust to the new restrictions.

"Everything - the first time, it's hard," he said.

Fran Vitolo of West Milford agreed. "People start acting like animals," she said.

Wayne Police Chief John Reardon was cautiously optimistic that the gas rationing rules imposed late Friday would alleviate some of the problems that have plagued gas stations in recent days.

"I would hope it would help to mitigate some of the frenzy at these gas stations," Reardon said.

"Getting more gasoline here is the real key," he said.