Frequently Asked Questions
Have a question? For answers to some of the most frequently asked questions about I-15 CORE, click on the questions below. If your question isn't listed here or if you want more information, please contact us.
- Why is this project needed?
I-15 CORE is needed to restore aging infrastructure, address long-term transportation needs and improve the mobility of goods and services throughout the state. Utah County is one of the fastest growing counties in the nation and the second most populated county in Utah, with nearly 20 percent of the state's total population. The Governor's Office of Planning and Budget estimates this growth trend will likely continue into 2060.
- What is included in the project?
As the largest road construction project in Utah history, I-15 CORE will add two lanes both northbound and southbound on I-15 for 24 miles from Lehi Main Street to Spanish Fork Main Street and extend the Express Lane from University Parkway in Orem to Spanish Fork. The project will also rebuild or reconfigure 10 freeway interchanges and replace or restore 63 bridges, many of which were built in the 1960s. The entire corridor will be paved with a 40-year concrete, and the work is expected to meet traffic demands through 2030.
- What was the original project area for I-15 CORE?
The original environmental study stretched from Draper to Payson. In March 2009 the state legislature approved a budget based on conservative cost estimates that would enable the most critical portion -- from American Fork Main Street to Provo Center Street -- to be built. Because construction costs have decreased and competition was high, UDOT was able to maximize the designated funds and extend the project north to Lehi and south to Spanish Fork.
- Why did UDOT choose to expand this section of I-15 first?
To maximize funding bonded by the legislature, the project team identified various construction scenarios that would meet the most pressing transportation needs for the potential investment dollars available. The corridor section starting at Lehi Main Street and moving south was determined to have the most immediate need for improvement based on current and projected levels of traffic on the roadway, the freeway's ability to handle that traffic, incident history, aging structures, cost and the potential for cost reduction. The northern and southern points of the original project area will be built as funding and need are determined.
- Who is building I-15 CORE?
Provo River Constructors (PRC), a consortium of expert local, regional and national contractors and engineers, proposed the greatest value solution for the project within the fixed budget. The team is headed by Fluor Corporation, Ames Construction Company, Inc., Ralph L. Wadsworth Construction Company, Inc. and Wadsworth Brothers Construction Company, Inc., which all have experience working on large transportation projects in Utah and in other areas of the country. The consortium includes more than 30 subcontractors and employs more than 1,500 workers. The team presented innovative ideas to keep traffic moving during the massive reconstruction effort and finish the project nearly two years faster than required. UDOT's I-15 CORE team of experts has oversight and ensures the contract provisions, quality, safety, budget and deadlines agreed upon are met.
- What changes were made to the design of the Provo Center Street interchange?
Though the original rotary interchange design submitted by Provo River Constructors was a high-functioning concept, UDOT and the contractor collaborated closely with the Provo City mayor, city planners and engineers to build upon the proposed design and create a modified diamond interchange. The modified design facilitates east-west movement, creates a more familiar traffic flow on and off the freeway and provides for direct access specifically to Draper Lane, fitting in with Provo City development plans. It also works around the challenges of existing topography like the rail line and development.
To stay on schedule and avoid additional cost, Provo Center Street and the interchange ramps will need to close at times throughout construction, but no closures will exceed 90 days. The interchange will be functional by December 2012, with final work on east-west local streets complete by June 2013.
You can view an interactive map of the new interchange design at http://i15core.utah.gov/flash/interchange_diagrams/provocenterst. An animated tour of the interchange is also available at http://www.youtube.com/watch?v=zyhAyh8cgwU. - How is UDOT addressing the s-curves on I-15 in Provo?
UDOT is improving the entire project corridor to meet all of today's design standards, including the s-curves between University Parkway in Orem and Provo Center Street and other curved areas on I-15 from Lehi to Spanish Fork. Specific improvements to the s-curves in Provo include widening shoulders, installing high-mast lighting, minimally straightening curves horizontally, changing some of the vertical grades to increase visibility and sight distances and improving barriers.
- What changes are being made to reconfigure the Spanish Fork Main Street and U.S. 6 interchange?
I-15 CORE is reconstructing the Spanish Fork Main Street and U.S. 6 interchanges, allowing the two to work smoothly as one. When complete, motorists will notice several changes to the way traffic moves through this new interchange including changes in the number of ramps and the exit and entry locations.
The exits to Spanish Fork Main Street and U.S. 6 will be combined. This means that the location of the southbound off-ramp to Main Street will be moved to the same location as the old U.S. 6 off-ramp. The combined exit ramps will replace the old loop ramps and merge areas in the previous interchange, increasing efficiency by keeping traffic travelling between I-15 and U.S. 6 off the local streets.
At project completion, the new U.S. 6 bridge over I-15 will carry both east- and westbound traffic. Traffic will be controlled by a signal on the bridge. Spanish Fork Main Street will be widened to three lanes in each direction with a dual-left turn lane from southbound Main Street to northbound I-15 and a single left turn lane from northbound Main Street to southbound I-15. The project will also replace the sidewalk, curb, and gutters in this area. - How will the project improve pedestrian access?
I-15 CORE will not only increase access for motorists but also allow for safe east-west passage of pedestrians and cyclists. A new trail from 1600 North to 1100 West via Provo Center Street to the west side of the freeway is a good example of improved access. Access to some existing trails may be restricted during construction for the safety of bicyclists and pedestrians. Information on these closures can be found along with road closure information on the project website, udot.utah.gov/i15core.
UDOT will also add a pedestrian underpass from Sandhill Road to Utah Valley University, improving traffic flow on University Parkway and encouraging safe pedestrian access to the university. - What is the Diverging Diamond Interchange (DDI) being constructed at American Fork 500 East?
The DDI being constructed at American Fork 500 East is a European design that will improve traffic flow and enhance safety in a fiscally responsible way. One unique feature of the DDI is that it eliminates left-hand turns against oncoming traffic. This DDI will be similar to the one at American Fork Main Street/Pioneer Crossing that opened in 2010.
You can view an interactive map of the new DDI at American Fork 500 East here: http://i15core.utah.gov/flash/interchange_diagrams/500e. - Why is concrete being used instead of asphalt?
A more durable 40-year concrete pavement will replace the existing asphalt surface on the I-15 CORE project for two main reasons: it has a longer life and it requires less maintenance than asphalt.
- Will my area receive a sound wall?
Sound walls are being constructed at locations where sound levels meet the minimum criteria and a wall was requested by a majority of the affected residents. To find out if your area will be receiving a sound wall, please contact the sound wall hotline at 801-763-5255.
- What is the project timeline?
I-15 CORE has an aggressive timeline designed to minimize long-term inconvenience to the public. UDOT and PRC are employing innovation and working around the clock to minimize inconvenience and complete the project quickly. Construction began in spring 2010 and will be completed in December 2012, nearly two full years ahead of the required schedule. For the current percentage complete, visit the I-15 CORE home page, udot.utah.gov/i15core.
- How is I-15 CORE funded?
I-15 CORE is funded entirely by the state of Utah. In March 2009, the governor and state lawmakers approved a $1.725 billion bond to fund the most critical area of I-15 CORE. UDOT supports the governor and legislature in recognizing the importance of investing in transportation and its positive impact in supporting a recovering economy.
- How will UDOT keep the project on budget?
I-15 CORE has a fixed budget. UDOT used a fixed-price, best-design process to select the contractor team, which means the team is under contract to complete the project for the set budget. By agreeing to a construction budget up front, UDOT has been able to maximize the designated funds and will get more project completed for the budget available.
- What is being done to minimize driver inconvenience during construction?
This project's section of I-15 through Utah County is an interstate corridor that affects traffic flow statewide. We recognize in our effort to complete the project as quickly as possible, there will be periods of time with significant restrictions and traffic delays. One of the strengths of the contractor's proposal is how lanes are remaining open during the majority of construction to minimize driver inconvenience. Some ways this is being accomplished include:
• Interstate and lane closures are avoided during heavy travel hours whenever possible. To date, 93 percent of all closures have been during overnight or low-travel hours.
• Lanes have been narrowed and shifted to accommodate more traffic while new lanes are constructed.
• Sophisticated traffic modeling is used to identify route detours.
• Signals on major surface streets such as State Street, University Parkway and University Avenue, are being timed with Orem and Provo cities to improve traffic flow and relieve traffic congestion on I-15. - Why does traffic have to split or shift from one side of the freeway to the other?
To keep the existing number of lanes open throughout the project for the majority of construction, lanes have been narrowed and shoulders reduced on I-15. This allows the contractor to shift all existing lanes to one side of the freeway (or in some areas to the outside or inside) while the other side is constructed. Shift points are put in place to transition traffic from one side of the freeway to the other.
To pave new lanes through narrow topography and varying grades on I-15 in American Fork and Orem, UDOT and PRC worked together to create a lane split plan to accommodate the work in summer 2011. The lane splits help avoid a long-term lane closure on I-15, prevent additional congestion and significantly reduce the inconvenience to drivers.
Motorists are encouraged to become familiar with lane shifts and splits before traveling and to pay attention while driving to ensure they are in their desired lane. Local drivers are further encouraged to stay on local roads and avoid using I-15 for short trips within the area to reduce congestion. - How can I reduce traffic delays?
Drivers can employ several TravelWise strategies to reduce delays through the I-15 CORE project. Avoiding heavy travel times, such as the morning and evening commute, is one way. Carpooling or vanpooling, trip chaining and telecommuting are other methods for reducing delays due to construction. One important strategy is to stay informed about construction activities by visiting the I-15 CORE website, udot.utah.gov/i15core, subscribing to weekly email updates or texts (text "i15" to 53535) or following the project on facebook and twitter.
- How is UDOT working with businesses?
UDOT is proactively working to help businesses plan and adapt during construction. Businesses are encouraged to implement various TravelWise strategies to cope with construction, including teleworking, offering flexible work hours and encouraging carpool and vanpool programs. The project communication team also meets one on one with businesses to create TravelWise plans tailored to specific needs. Contact Christina Davis at 801-341-6426 or christinadavis@utah.gov to set up a meeting.
I-15 CORE also has area-specific representatives to assist businesses with information on current and upcoming activities. To contact your area business representative, select from this list: http://www.i15core.utah.gov/downloads/public-involvement-coordinators.pdf. - How can drivers stay informed of construction plans and potential delays?
UDOT has a comprehensive public information campaign to provide up-to-date construction information. Resources include:
Website: udot.utah.gov/i15core, where drivers can ask questions and sign up for weekly email updatesHotline: 888-i15CORE (888-415-2673)
Email: i15core@utah.gov
Text updates: text "i15" to 53535
Facebook: www.facebook.com/i15core
Twitter: www.twitter.com/i15core - What travel alternatives are available during construction?
The success of the project will require cooperation and a partnership between UDOT and the public. UDOT's TravelWise program encourages working from home one to two times per week, adjusting travel times and traveling during non-heavy travel times, carpooling, avoiding errand running during rush hour, running several errands at once instead of making multiple trips and, where possible, walking or biking to destinations. For more information on these travel solutions, visit travelwise.utah.gov.
- Will UTA's FrontRunner be a transportation alternative during construction?
Public transportation is a great alternative and part of a balanced transportation solution. The state and UTA are making positive efforts to expand public transportation and make it available to a greater number of people. Although it won't be complete before I-15 CORE is finished in December 2012, FrontRunner South will be an efficient alternative travel option for future growth in Utah County. During I-15 CORE, buses will operate throughout the corridor, helping to alleviate congestion. For information regarding UTA's FrontRunner South construction project, please visit the project website at rideuta.com or contact Marc Bowman at mbowman@rideuta.com..
- My windshield was hit by a rock and was damaged. Will UDOT pay for it to be repaired?
Neither UDOT nor the contractor is generally liable for rocks thrown by other cars or trucks. However, I-15 CORE may help pay for damage caused directly by debris or materials falling from PRC construction vehicles. If your windshield was damaged by a rock or debris dropped or thrown from a construction vehicle, please contact the I-15 CORE hotline at 888-I15CORE (888-415-2673) and provide the details of the incident (date, time of day, location, etc.), including a truck number or license plate number.
- How often do crews restripe lane markings?
Every effort is made to ensure the safety of drivers through the construction project. Maintaining striping in an active construction zone is always a challenge, especially in cold and wet temperatures. I-15 CORE crews monitor the lane striping 24-7, and when weather permits, crews regularly re-stripe areas that are faded. If there is a specific area of concern, please contact our hotline at 888-I15CORE (888-415-2673).
- How can I work for the I-15 CORE team?
The contracting team responsible for construction of the I-15 CORE project is Provo River Constructors (PRC). You can contact them directly to find out about subcontractors/suppliers/employment at 801-653-3310.




