The problem: The running of the Honolulu Triathlon may keep the parking area in front of the shell closed until 2 or 3 p.m. Gates for the concert open at 3 p.m.

That means people who like to line up early for the best lawn seating for concerts at the outdoor shell will have to find alternative parking in the surrounding neighborhood, said city spokesman John Fuhrmann.

That will be made more difficult, however, by the periodic closing of some roads through most of the morning to accommodate the Honolulu ITU Triathlon World Championships.

"We're hoping to have the parking cleared by 2 p.m., so we're asking people headed to the concert not to arrive before then," Fuhrmann said.

Triathlon spokesman John Korff, however, said it could be 3 p.m. before the parking lot is cleared.

One or more lanes of traffic along the triathlon route will be closed or restricted between 9 a.m. and 1:30 p.m. During the bicycle portion of the race, which makes five loops around Diamond Head, the entire route (Diamond Head Road, some sidestreets, and parts of Monsarrat and Kalakaua avenues) will be closed.

"There will be periodic reopenings, though, so drivers can get through," Korff said.

City officials said some bus routes in the area will be canceled or detoured during the triathlon.

Officials said there should be fewer problems on Sunday, when more than 2,000 triathletes participate in the open section of the race.

But don't relax just yet.

Over at the Blaisdell Center, both the Spring New Product Expo and performances of the Broadway musical "Cats" are expected to draw large crowds to the surrounding parking areas throughout the weekend.

Best advice: Get there early for all the events.

Reach Mike Leidemann at 525-5460 or mleidemann@honoluluadvertiser.com.