DENVER -- Traffic on Interstate 25 was tied up for more than 12 miles Tuesday morning after two left lanes of southbound I-25 between Arapahoe Road and County Line Road were closed for construction crews.

Thousands of drivers were frustrated with the resulting parking lot.

"As I got to the bottom of the flyover from Hampden, people were putting on their flashers and going off the entrance ramp the wrong way -- where it comes off the entrance ramp there -- to get out of that situation," said Jim Jennings, who was stuck in the morning commute.

Normally, T-REX construction is completed before the morning rush hour but several trucks were late on Tuesday, delaying the project and extending the time for the road closure until 9:45 a.m., said T-REX spokeswoman Karen Morales.

During the "milling and overlaying" portion of the massive freeway construction project, a truck rips up the highway asphalt and is followed by another truck that sweeps up all the crumbled asphalt. However, the problem arose when the trucks that come behind to pick up all the asphalt didn't show up to the Tech Center work zone on time, Morales said.

There were a number of other factors that also contributed to the logjam and construction delay. Those factors are being investigated, Morales said.

One of the streets sweepers had apparently broken down and the contractors did not dispatch another crew to the scene fast enough, Morales said.

Southeast Corridor Constructors, the contractor in charge of the project, could face fines for the delay. The highway is required by contract to be open by 5:30 a.m. following overnight construction work.

"I would like to extend a personal apology to the motorists who were inconvenienced by this morning's delay," said Bill Murphy, project manager for Southeast Corridor Constructors. "Minimizing public inconvenience is our No. 1 goal, and one that we take very seriously. Our management team is in the process of identifying the root causes of what contributed to this situation, and implement the necessary procedures and backups to ensure this doesn't happen again."

The asphalt milling and overlay project through the Denver Tech Center is part of the final widening and paving of I-25 south of Belleview Avenue, which is expected to be complete by the the end of 2004.