This is an archived article that was published on sltrib.com in 2012, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

The massive $1.7 billion reconstruction of Interstate 15 in Utah County is shifting out of the phase that has been adding lanes along its mainline to rework Orem interchanges — one at a time — starting this weekend with a closure of University Parkway at I-15.

"This will be a year of interchange construction," said Todd Jensen, project manager for the Utah Department of Transportation. "The project is 75 percent complete, so the end is near [expected in December]. But we still have a lot of work to do this year that will impact traffic."

First up is a closure of University Parkway at I-15 beginning Friday at 9 p.m. until Monday at 5:30 a.m. for signal work. The southbound on- and off-ramps of I-15 there are also scheduled to be closed for ramp reconstruction and paving.

In coming weeks, several closures and restrictions are scheduled for University Parkway. Crews are adding a new continuous flow intersection, or CFI, near I-15 at Sandhill Road at the entrance of Utah Valley University. It will be the first CFI in Utah County. Such intersections are common along Bangerter Highway in Salt Lake County.

CFIs eliminate separate left turn signals at intersections to help speed traffic flow. Drivers seeking to turn left off University Parkway will enter special left turn lanes well before the intersection itself. Signals will allow them to then cross over traffic into new extreme far left lanes that will allow left turns onto Sandhill at the same time that through-traffic on University proceeds straight.

An animation of how the redesigned interchange and new CFI will work is online at bit.ly/Irqu7F.

Jensen said work on the CFI originally was designed to last through December, but contractors and UDOT found ways to complete it by the end of May. He said that will help when UVU fall classes begin, "and it will also help when we work on those other Orem interchanges to have full use of University Parkway."

Reconstruction of other interchanges will then come to the north half of the 1600 North interchange in Orem, scheduled to close as early as April 23 for 30 days.

Next, work on the 800 North interchange will close it for up to six weeks. Then work on the Orem Center Street interchange will close it for up to 30 days. Work then will return to the south half of the 1600 North interchange, and will take 30 days.

"We are only closing one interchange at a time. Obviously, if we did them all at the same time, access to Orem would be impossible," Jensen said.

Meanwhile, the northbound on-ramp at Provo Center Street is also scheduled to close as early as April 29 for up to 40 days. Once it reopens, the northbound off-ramp is scheduled to close, also for up to 40 days.

"There will also be ongoing work on the U.S. 6-Spanish Fork interchange, but not with as many big closures," Jensen said.

Jensen encourages drivers to keep up with construction and restrictions by checking the i15core.utah.gov website, signing up for email updates or following the project on Facebook or Twitter.

Jensen said that UDOT research shows that for such a large highway project — costing at least $1 billion — it is the quickest-completed project of its kind in U.S. history. The 24-mile project from Lehi to Spanish Fork is now scheduled to be completed in 35 months, or just under three years, from start to finish.

He said most projects of that magnitude take at least five years, and some have taken up to 12 years. Jensen said the project generally has kept its original number of lanes open, with only short-term reductions, during construction.

Jensen said the project has paved 250 lane-miles with new concrete, or enough to pave a two-lane highway from Salt Lake City to Wendover.