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 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.
For finishing the job on budget and well ahead of their Dec. 24 deadline, the contractors are expected to receive a bonus close to the contract maximum of $27 million.
Few people could have been as happy about the opening as Steve Williams, owner of Bobby and Steve’s Auto World, a gas station right off the south end of the bridge. The old bridge carried over 140,000 vehicles per day and its loss aggravated traffic congestion and hurt many businesses.
Williams said his store saw its gas sales drop 10 percent to 15 percent after the disaster. To draw customers back, he and his crew stood on the exit ramp across the street and handed out $25 gas cards to the first 100 drivers entering downtown via the new bridge.
Orlando Lewis, who lives close to the bridge, recalled crossing over the old bridge just 30 to 45 minutes before it collapsed, but said he had no worries about the new span.
Lewis said he had to slow down as he crossed just to take in the size of the new bridge. It’s 76 feet wider than the old span, with wide shoulders that could be used to carry more traffic or mass transit in the future.
‘‘Now to have wide lanes in our city is a blessing,’’ Lewis said. ‘‘It’s unfortunate that had to come this way, but going across that bridge now is like a luxury.’’