Welcome to downtown Tampa, where the price of success on a busy weekend is gridlock, confusion and delay.

Take Saturday, April 30, perhaps the most crowded weekend day downtown Tampa has ever seen. Nearly 70,000 people converged on the central business district:

• 30,000 at RiverFest, which took place at five different parks along the Riverwalk.

• 20,000 at Amalie Arena for a Tampa Bay Lightning playoff game.

• 15,000 at the Tampa Convention Center for a cheerleading competition.

• 3,500 to 4,000 for shows in all five theaters at the David A. Straz Center for the Performing Arts.

And, naturally, many of them arrived by car.

"A perfect storm," top city business official Bob McDonaugh told the City Council on Thursday. It was bad enough that the Straz Center held the curtain for 40 minutes so that patrons caught in traffic wouldn't miss the start of Beautiful: The Carole King Musical.

The problem on Tampa's biggest weekends — about 14 of them a year — is bad enough that the city is looking at the possibility of running shuttles on a loop among main event venues and parking garages that are largely empty.

City Hall already sends out traffic advisories on weekends with lots of events, but this week staffers from parking, traffic, police and public works met to discuss what they could do differently in the future.

In addition to asking the Hillsborough Area Regional Transit Authority the cost of running shuttles, Mayor Bob Buckhorn said the city could adjust the timing of traffic lights and add officers to traffic duty.

He said the city also ought to make better use of signs, encourage visitors to think about parking in garages in Ybor City and use the trolley to get to downtown, and get people to use Cass and Cypress streets to get to Interstate 275 instead of only using Ashley Drive.

The mayor said he called for the staff meeting after seeing comments on Twitter and Facebook saying that people had a good time at RiverFest — but complained about traffic and parking.

"I wasn't particularly happy with how we performed at RiverFest," he said. "If we're going to continue big events like that, we really have to get the ingress and egress and the parking down to a science and be prepared to accommodate big crowds. . . . Moving forward, we have to do better."

When the city sends out traffic advisories, the Straz Center tries to pass that information along to patrons via email. And while theaters routinely start a few minutes after the advertised time, it's rare to hold the curtain as long as it did that weekend, Straz spokesman Paul Bilyeu said.

And another big weekend is coming up this Saturday and Sunday, with matinee and evening shows for Disney on Ice at Amalie Arena.

"We're not complaining," City Council member Harry Cohen said. "The city's doing great. It's just the growing pains of an embarrassment of riches."

Contact Richard Danielson at rdanielson@tampabay.com or (813) 226-3403. Follow @Danielson_Times