No Extra Security at Pacific’s GNR Show : Concert: Amphitheater officials say they’re sufficiently prepared but plan to take measures to keep the traffic from turning into a nightmare.

COSTA MESA — No extra security is planned inside the Pacific Amphitheatre for Thursday’s Guns N’ Roses show, even though 60 people were injured in a riot when the band played St. Louis recently.

“We feel that we prepared well in the beginning,” Susan Rosenbluth, the Pacific’s general manager, said Tuesday. She noted that Nederlander West Inc., operators of the amphitheater, also promoted two Guns N’ Roses concerts in May at the Pantages Theatre in Los Angeles and that there were no security problems.

However, Rosenbluth will be meeting again with officials of the Costa Mesa Police Department and the Orange County Fair in an effort attempt to head off potential traffic problems before and after the concert, one of three that come during the fair this year.

The amphitheater is on the fairgrounds. This is the first year the Pacific has booked concerts during the fair since 1986, when a Beach Boys show contributed to a nightmarish traffic situation.

But traffic was not as bad as expected during the first of this year’s three shows, a Gloria Estefan concert Friday. In fact, Costa Mesa police officers on the scene said that traffic seemed no heavier than for a typical concert at the amphitheater. However, Rosenbluth said, the Guns N’ Roses audience is expected to exceed Estefan’s crowd of 15,000 by 3,700.

Under a new traffic plan, more than 50 officers were on hand near the fairgrounds and amphitheater Friday to help alleviate congestion, and shuttle service to several satellite lots was instituted. The extra officers will be on hand again tonight as Joe Cocker and Los Lobos perform, starting at 8 p.m. The amphitheater box office would not release ticket sales figures for tonight.

In St. Louis, Guns N’ Roses singer Axl Rose leaped into the crowd to grab a camera from a fan and then led the band off the stage. A melee erupted, resulting in the injuries and in $200,000 in damage. Rose later blamed the incident on lax security.