The newly announced project estimated to cost $120 million will add express lanes from North Salt Lake to Farmington, replace seven old bridges there and rework two other major interchanges at 2600 South in Woods Cross and 500 South in Bountiful (including improving access through them for pedestrians and bicyclists).
Work is expected to start early next year, Peterson said, and take about two years to complete.
UDOT had long planned three separate projects in Davis County, he noted one to extend the express lanes, one to replace deteriorating bridges and another to rework problematic interchanges.
"When we obtained funding to do the express lanes," Peterson said, "we decided to try to combine the projects into one to reduce disruption."
He added that UDOT is putting out a request for proposals now to contractors to do the design-then-build project and hopes to have a winner under contract by January.
UDOT has enough funding to expand northbound express lanes between where they end now in North Salt Lake and where they begin again in Farmington, Peterson said. "And we will build southbound lanes as far as we can afford to," depending on how the bids come back.
Bridges are expected to be replaced at the 2600 South and 500 South interchanges and at 1500 South (two each in each spot, one for each direction), plus a single bridge over I-15 at 400 North. Peterson noted several of the bridges are old, and concrete falling from beneath them has caused problems.
UDOT is allowing total closure of the freeway for up to five weekends during the project for bridge-replacement work. Officials anticipate that contractors likely will choose to build bridges to the side of the freeway, and move them into place over a weekend.
"We have some good alternative routes," including Legacy Parkway for those weekend closures, Peterson said.
Officials anticipate that all current lanes will remain open during peak hours, with nighttime lane restrictions at various periods throughout the two-year project.
The Davis County project is not as major as the other work at the Point of the Mountain. "That is a total reconstruction of the freeway there. In Davis County, we are just squeezing in new express lanes plus the other work," Peterson said.
The project at the Point of the Mountain which has the official nickname of "The Point" is a $247 million effort to rebuild seven miles of I-15 between Draper and Lehi during the next two years.
It will also 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.
UDOT has said that is the last major section of I-15 on the Wasatch Front that has not been reconstructed in recent years. It is about 50 years old, and at the end of its life span. Sections of pavement there often have buckled in recent years because of dirt and debris clogging temperature expansion joints.
The new projects come after UDOT last December completed a massive $1.7 billion project over three years to rebuild and expand most I-15 stretches in Utah County.