Washington basketball fans gritted their teeth, clenched their fists and snaked along packed roadways to welcome Patrick Ewing to the opening event in the Patriot Center at George Mason University last night.

At the same time, some residents of the area, west of Fairfax City, formed watch brigades during the evening rush hour to confirm their fears that roads that are overcrowded in the best of times would be strained beyond their limit by thousands of additional cars.

Many of their fears appeared to come true as Braddock Road and parts of Rte. 123 virtually became two-lane parking lots.

Stuck in traffic six miles from the arena, Allen Poltlin, a resident of Annandale, finally gave up. "I'm going home," he said. "Maybe I"ll try it again in the second quarter."

George Mason officials disputed the severity of the congestion, saying that they handle more cars every weekday morning when the school is in session than they did last night.

"We can't satisfy some people," said Donald J. Mash, George Mason's vice president for administration.

"We set up a process that would allow all neighbors to take part in discussions. The traffic situation here is not nearly as bad as people had feared."

As local officials cut ribbons and helped themselves to vast molds of salmon mousse, thousands of eager fans were inching toward the game in their cars.

"This is a state university, and the city had no say whatever in how the land was used," said Sharon Bulova, who spent the early evening monitoring her neighborhood for the Kings Park Civic Association. Most of the roads leading to the arena are in Fairfax City. "The traffic problems are going to create drastic problems for the areas around the arena."

University and county police were assigned to traffic control last night, and most streets in and out of the center made were one-way to help ease the flow of cars to the game.

Neighborhood activists said they were concerned about the possibility that many people will drive and sometimes park along the residential side streets near the Patriot Center.

The 10,000 seat arena will be the scene of several rock concerts in the coming months, and some residents who live along Braddock Road say they are afraid that they will be unable to get in and out of the area on those occasions.

Local politicians on hand for the inaugural event joined with fans to express concern for the roadways leading to the center.

"I'm impressed with this place. Its hard not to be," said Alexandria Mayor James P. Moran Jr. "I have to admit though, it was a little tough making it down Braddock Road."

"I drove here from New York to see Patrick play his first game," said Darrell Mack, as he watched the New York Knicks and the Washington Bullets warm up for their preseason game to the throbbing theme music from "Miami Vice." He added: "But it took me almost as long to drive the last 20 miles as it did to get to D.C. from Manhattan."

Discord was not the only note sounded by neighbors last night, as many appeared happy enough to have the arena and willing to suffer a little to take advantage of the place.

"It took me almost three hours to get here from College Park," said Mike Baker, who lives near the arena. "But I don't care about the traffic. This is an opportunity and we should be grateful for it."