Construction workers put finishing touches with cement Monday on the new Interstate 35W bridge, which opened to traffic Thursday in Minneapolis. The new bridge replaces the bridge that collapsed Aug. 1, 2007, into the Mississippi River, killing 13 and injuring more than 100. The vertical structure is called the Gateway monument.

Minneapolis ? Emergency vehicles with lights flashing led twin processions to open the new Interstate 35W bridge before dawn Thursday, less than 14 months after the shocking and deadly collapse of its predecessor.

Highway department trucks followed patrol cars, fire trucks and ambulances in slow northbound and southbound parades that passed each other around the middle of the bridge just after 5 a.m. Behind them were hundreds of motorists in cars, motorcycles, trucks and buses, many of them honking their horns and a few waving American flags.

Traffic was initially heavy on what had been one of the Twin Cities’ busiest arteries, but it loosened up quickly and it continued to zip along through the morning rush hour. The old bridge had three lanes in each direction, but its replacement has five.

“It was wonderful. What a beautiful bridge. It’s terrific,” said Donald Brown, a retired truck driver from Golden Valley who was among the first to cross the new bridge over the Mississippi River in downtown Minneapolis.

The old bridge fell Aug. 1, 2007, killing 13 people and injuring 145 others. The sudden collapse of steel and concrete jolted Minnesota and other states into taking a harder look at the safety of thousands of aging bridges across the country.

The state put the $234 million replacement on a fast track, and contractors had it ready for traffic on budget and more than three months ahead of deadline.

“Remarkable,” Brown said. “That they did it as fast as they did is unbelievable.”

To Garrett Ebling, one of the most severely injured survivors, it was a surreal moment to watch video of the procession and all the honking horns. The Plymouth man said Thursday was a harder day for him than the first anniversary of the collapse.

Ebling has returned to work in public relations and gotten married since the collapse but said he’s still dealing with the psychological and physical effects. He wasn’t sure when he’ll make his first trip over the new bridge.

“It’s not that I’m afraid to cross it, it’s when I do it, it will be on my own time, and when I do it I’m sure it will be difficult,” he said. “I’ll have a lump in my throat and a twist in my stomach.”

The National Transportation Safety Board has not yet issued its final determination of what caused the old bridge to collapse, but officials have been focusing on an error in the original design and the weight of construction materials that were on the bridge for a resurfacing project when it fell.

Unlike the old bridge, the new bridge is built with redundant systems so that if one part fails it won’t collapse. And it contains 323 sensors that collect data on how it handles the stresses of heavy traffic and Minnesota’s harsh climate. The data will help engineers maintain the bridge and advance the art of bridge design.