The average price of a gallon of gasoline in the Washington area has hit $1.13, and supplied remain so tight that short gas lines are forming from time to time.

Texaco, which provides about 5 percent of the gasoline sold in the area, plans in February to begin selling gasohol -- a mixture of gasoline and alcohol -- in about 125 stations here, but it is not thought that this will significantly ease the overall supply problem.

"I don't believe these prices, but I think we're going to see more [price increases soon]," said Glenn Lashley, a spokesman for the American Automobile Association.

The AAA's most recent price survey, taken last Friday, shows that regular gasoline is selling for an average of $1.103 a gallon, unleaded $1.136 and premium $1.155 at full-service pumps. Self-service prices were somewhat less.

Stiff price increases announced last week by Exxon, Texaco, Shell and other companies may not have been reflected at the pumps when the AAA survey was made. The average price for all grades taken together -- $1.128 -- represents a 7 1/2-cent increase in one month.

Supplies of gasoline available here and nationwide are less this month than in any month since February 1975, according to industry analysts. But they say that the effect of this is less dramatic than it might be because people have cut down drastically on their driving and because January is a month when people traditionally don't drive much anyway.

"It's a progressively worsening situation," said Vic Rasheed, head of the Greater Washington-Maryland Service Station Association. ". . . The oil companies are hoarding crude oil [and thereby] forcing it to go up in price that much quicker."

Ed Murphy, the statistician for the American Petroleum Institute, an industry organization, confirmed that the nation's crude oil stocks held by the oil companies are unusually high now and "have been building ever since early fall."

Murphy said this is because demand for gasoline is down as people conserve, and because the companies built up their stocks in order to beat recent worldwide crude oil price increases and to hedge against possible future supply distruptions.

"We're on the fine edge, but at the same time, if everybody keeps his head we'll be fine," said Sunoco analyst Joe Strain. "I don't see us returning to a situation of late spring or early summer" when there were long gas lines in the Washington area.

Out at the pumps yesterday, dealers described how tight their supplies were.

"I'm down to the bone right now," said Alexandria Exxon station manager Dennis Kane. "We're running short." Nearby Sunoco dealer Rick DuBrueler said that on Sundays, when he is the only dealer open in the area, a gas line half a block long sometimes forms.

The manager of Bob Shelton's Georgetown Gulf said supplies are touch and go. "I'm out of unleaded, I'll be out of regular in about an hour, they quit making premium," said manager Charlie Shelton, the owner's son.

He said he put up an out-of-gas sign at one point "just to deter a few" customers. The manager at an Amoco station at 13th and L streets NW said he did the same thing yesterday when he ran out and had to wait for a tanker truck to make a delivery.

Texaco plans to make its gasohol announcement during the next few days. In all, the company plans to sell gasohol in about 500 stations in Maryland, Virginia and the District of Columbia. It already sells gasohol in about 600 stations elsewhere in the country.