Thousands flocked to the opening celebration on March 3, 2012 of West Dallas’s new link with downtown, the Margaret Hunt Hill Bridge. (Credit: Andrea Lucia/KTVT)

DALLAS (CBSDFW.COM) – Thousands flocked to the opening celebration Saturday of West Dallas’s new link with downtown, the Margaret Hunt Hill Bridge.

Festivities began early with a 5k and 10k levee run, which had participants jogging across the bridge itself on their way to the Design District. Organizers say Saturday’s event is one of only a few times residents will be allowed to walk on the bridge.

There are no sidewalks, so the nearby Continental Street Viaduct will be turned into a dedicated pedestrian zone, City Manager Mary Suhm said.

The bridge’s designer, famed Spanish architect Santiago Calatrava, was on hand at Southern Methodist University before the event, saying the bridge is “landmarking the new center of Dallas for the 21st century.”

“I believe, like many other people believe, the Trinity River has a huge importance for the character of the city,” he said. “I’m completely convinced that in 100 years the city on both sides will have a different character.”

Construction on the bridge began in 2007. It will link Woodall Rogers Freeway in downtown to Singleton Boulevard in West Dallas. City leaders hope the bridge will help spur redevelopment in West Dallas and North Oak Cliff.

“Many other bridges will come and we’ll have a gigantic center of Dallas on the Trinity River,” Calatrava said.

The bridge’s capacity Saturday at any one time is 6,750. City spokesman Frank Librio said early estimates expect that 20,000 visited the bridge throughout the day, which lasted from noon until 9 p.m.

At 5 p.m., event staff says there were about 2,900 people there. Two hours later, Librio said the city had to begin to limit admission because attendance reached capacity.

From left, former Dallas Mayors Tom Leppert, Laura Miller, Ron Kirk –– now the U.S. Trade Representative –– and current Mayor Mike Rawlings speak at the opening celebration of the Margaret Hunt Hill Bridge on March 3, 2012. (Credit: Phyllis Smith/KRLD)

“It’s rather impressive, it’s big,” said Carlos Alvarez, a resident who visited the bridge during the event. “I didn’t realize how big it was driving past it every day. Very nice, very beautiful.”

The bridge is about a third of a mile long. Event organizers were careful to tell visitors that the suspension bridge will sway slightly in the wind: There’s no danger in that.

Evening festivities include a concert by Jonathan Tyler and the Northern Lights and a fireworks show.

This is the first of three planned Calatrava bridges: Construction is slated to begin on the Margaret McDermott Bridge next year. That one will link Interstates 30 and 35.