"It's the last major section of I-15 along the Wasatch Front that has not been replaced. It is about 50 years old, and is at the end of its life-span," said Utah Department of Transportation spokesman John Gleason.
The previous two biggest projects to rebuild I-15 included replacing most sections in Salt Lake County before the 2002 Olympics, and a massive $1.7 billion project to replace most Utah County stretches completed in December.
"We're in the early stages of assembling a project team to develop the contract requirements and bid documents for construction proposals," said Tim Rose, UDOT's director for the new project.
"Our goal is to have a contractor on board early in 2014 so that we can take advantage of a full season of construction work next year and finish all the improvements by the end of 2015," he said.
The commission, meeting in Heber City, received a report Friday on some of the improvements planned.
The project will widen I-15 to six lanes in each direction from 12300 South in Draper to the Timpanogos Highway (State Road 92) at Thanksgiving Point. Some areas in that stretch now have four lanes, and some have five.
Crews will add new concrete pavement designed to last at least 40 years.
They also will replace bridges at 14600 South in Bluffdale and realign the frontage road there and at the Timpanogos Highway to accommodate future upgrades. The bridges will be designed to have at least a 100-year lifespan.
UDOT officials told the commission that without the upgrades, forecasts show that traffic would slow to stop-and-go in that area by 2020.
The project should also solve a recurring problem with buckling of pavement segments in the area in recent years.
Gleason said that in winter when sections of the freeway contract because of cold temperatures, dirt and other debris enter and clog expansion joints. Then in the summer when the sections try to expand, the clogged joints can't handle it and the pavement buckles.
This problem has forced several emergency closures of I-15 in recent years. "It would be closed for about five hours at a time," Gleason said, as crews would cut out and repair portions of buckled sections.