Kiewit earned a $300,000 bonus on the quick completion Sunday of the I-405 freeway partial bridge demolition in Los Angeles. The contractor had faced penalties of $72,000 an hour for any delays past the agreed shutdown time.

But thanks to a massive media attention and some lucky construction breaks, the work was completed 17 hours ahead of schedule and “carmeggedon” was avoided.

“We were before the world, streaming live and we needed to perform,” says Dan Kulka, communications manager for Kiewit Infrastructure West, the project’s lead contractor. “And we had an enormous amount of work to do and we only got 53 hours.”

Kulka says everything went smoothly on the project from the second the contractor and the California Dept. of Transportation closed a 10-mi portion of the freeway between the I-10 and U.S. 101 on Saturday night to tear down half of the iconic, three-span box girder Mulholland Bridge.

“If you gain a few minutes on every single different operation then you end up way ahead of schedule,” he says.

One of the most obvious reasons for the early, 11:30 am Sunday opening was public awareness and cooperation, which allowed Kiewit to close ramps precisely on time and utilize a full force of machinery and at least 100 workers.

Another reason was the freeway road surface below the bridge. Mounds of dirt were piled below the demolition work to catch falling bridge debris, but because of the possibility of damage to the roadway, Kiewit allowed significant time for repair. When the freeway was cleaned and swept, a team of inspectors went through and found zero damage, says Kulka.

“It was in great shape so we just striped it and opened it up,” he says.

But one of the biggest reasons for a timely completion was the strategic placement of two bridge columns once they were taken down. Kulka says that rather than demolish the columns on the spot, they were laid down on an adjacent hillside. He says the columns will be demolished when the second phase of the bridge project resumes next year.

“We could have sat there and chipped on those columns for another 17 hours and it would have been more efficient for us but we would held up the freeway that much longer,” he says.