But the delays have also been frustrating.
"We're behind by approximately two years of when we anticipated to have this project completed" in October 2011, Adams said. It dragged because UDOT forced the contractor, Flatiron/Harper Joint Venture, to fix numerous items that did not pass inspections, from cracking concrete pavement to drainage systems to barriers.
"Through the last two years, we have been charging our contractor liquidated damages for that extra time" beyond deadlines set by contract, Adams said. "To date, that has totaled around $6 million," charged at $15,000 a day.
The only piece remaining for such fixes, he said, is repairing cracks in a wall near the east end of the project's eastbound commuter lane. "We anticipate that the wall will be completed and that section will be opened later this fall," he said.
With that end finally in sight, UDOT prepared statistics on performance of the road so far for the Utah Transportation Commission.
It shows that traffic on the highway has increased by 14 percent since 2007, before construction began in 2009. But travel times have decreased by 63 percent with travel between Lehi and Highland dropping from 19 minutes to seven.
It went from a two-lane road to seven including two first-in-the-state commuter lanes that travel over or under crossroads to avoid traffic signals for 4 miles. Unlike freeway express or car-pool lanes, the commuter lanes are open to all traffic and do not require more than one rider.
UDOT data also say traffic accidents have fallen by 71 percent at interchanges since 2007, and by 25 percent elsewhere on the roadway. Adams said that is in part because of better overall movement and reduced congestion on the roadway, but it also results in large part from adding a "diverging diamond" interchange at Interstate 15.
This design eliminates all left-hand turns. "By doing that alone, you will see a big reduction in accidents," he said. That intersection eliminates left turns by having traffic temporarily crisscross to drive on the left-hand side of the roadway while passing under I-15.
Adams said that UDOT found in checking with Lehi that more than 100 new businesses have sprouted along or near the new project, and others have expanded including at the Traverse Mountain Outlets, Thanksgiving Park, Adobe, Xactware, Micron and IASIS Healthcare.
"One of the main reasons has been from improvements from our roadway," Adams said. "We estimate that's 4,000 new jobs in the area.
"We're very pleased with how it turned out," he added. "Sometimes we lose sight of the benefits of the project" because of frustration over the delays.
Of note, contractor Flatiron was part of a consortium that was paid $13 million by UDOT in 2010, when it contended it was cheated out of a $1.1 billion contract to rebuild I-15 in Utah County.
That project went to another consortium which had made big contributions to Gov. Gary Herbert after UDOT tweaked the original scoring of bid proposals.
Last year, Herbert said the swift, efficient rebuild of I-15 and the delays and problems with SR-92 vindicated the controversial state decisions about awarding the $1.1 billion contract on I-15.