I-15 expansion: Here’s what you need to know

How wide would it be? What would it cost? Why might it be needed? Whom might it help? Whom might it hurt? Why do so many oppose it?

(Rick Egan | The Salt Lake Tribune) Homes in both sides of Interstate 15 as it winds through Woods Cross on Thursday, Jan. 5, 2023. The state is proposing to expand the freeway between Farmington and Salt Lake City.

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It’s been more than two decades since NeighborWorks Salt Lake set up shop in the Guadalupe area with the aim of revitalizing the west side.

From there, it helped build new homes and mend old ones.

Now, a lot of that work — even its own office — might be threatened to make room for a wider Interstate 15.

“We’ve worked on this for a couple of decades,” Maria Garciaz, chief executive officer of NeighborWorks Salt Lake, said, “and the expansion will reverse all of that.”

Many Salt Lake City west-siders, Davis County residents and others share those fears. Why, they ask, is the Utah Department of Transportation proposing to enlarge I-15? Whom might it help? Whom might it hurt?

As a public comment period on two proposed alternatives for the freeway wraps up this week, we answer those questions and more about what could be one of Utah’s costliest I-15 expansions since a $1.59 billion overhaul in Salt Lake County before the 2002 Winter Olympics and a $1.7 billion rebuild in Utah County.

What part of I-15 would be widened?

(Christopher Cherrington | The Salt Lake Tribune)

The proposed expansion would stretch from Farmington’s Shepard Lane to Salt Lake City’s 400 South. It is a part of a long-term vision developed by the Wasatch Front Regional Council, a regional transportation planning agency, that includes transit upgrades and other roadwork in the area through 2050.

The I-15 piece assumes all other proposed projects in the long-range plan — including additional double track and electrification of the Utah Transit Authority’s FrontRunner commuter rail line — are made in the area, UDOT project manager Tiffany Pocock wrote in an email.

What’s the status of the I-15 project?

It is undergoing a state-funded environmental study to determine the impact of the various widening options.

UDOT announced some of these alternatives in November and is gathering feedback during a public comment period that ends Friday.

“It is not a question of I-15 or transit or bikes and pedestrian improvements,” Pocock said. “The long-range transportation plan has shown that improvements to I-15, FrontRunner and many other roadway, pathway and transit projects are needed by 2050 for the growing Wasatch Front metropolitan area.”

How much would the project cost?

UDOT estimated that an I-15 expansion would cost about $1.6 billion, which the Legislature initially has approved. That does not guarantee funding for such a project, Pocock said, but does indicate lawmakers’ intent to pay for one.

Is the widening definitely happening?

At this stage, UDOT includes a “no build” alternative, Dan Adams, a UDOT consultant, said in a virtual public meeting. So, currently, the two proposed alternatives are optional.

But, with a funding stream already identified, it’s unlikely that the agency wouldn’t move forward eventually with construction.

“It’s naive to believe that they would simply not do the expansion,” Salt Lake City Mayor Erin Mendenhall said. “It’s a matter of how they do it.”

What could an expanded I-15 look like?

In Option A, the corridor would include five general purpose lanes, an express lane and an auxiliary lane in certain areas in each direction. Option B would be similar, except the central express lanes could be reversed to serve morning and evening traffic demands.

The width would vary throughout the 17-mile corridor, Pocock said. Option A would put I-15′s mainline at about 226 feet wide, and Option B would grow the mainline to 246 feet.

The agency also outlined different possibilities for offramps, crossings, bike lanes and pedestrian pathways to improve community connections across the freeway.

The stretch of highway closer to Salt Lake City has room for widening already, so the new lanes could be added to that existing space in the center of the roadway.

Farther north, in Davis County, that portion of the highway has less center space and runs parallel to FrontRunner, which would push any proposed widening to the east.

Would widening I-15 make commutes faster?

(Rick Egan | The Salt Lake Tribune) Homes border both sides of Interstate 15 in Woods Cross, on Thursday, Jan. 5, 2023. The state is proposing to expand the freeway between Farmington and Salt Lake City.

Based on a 2019 study, it takes about 18 minutes during morning peak times to drive from Farmington to Salt Lake City along I-15, compared to 19 minutes in the evening.

Using future growth travel models, Pocock said, the study estimated that, without road upgrades, these travel times would balloon to 55 minutes and 66 minutes.

These models also take into account all improvements in the Wasatch Front Regional Council’s long-range transportation plan and assume all of its investments for area roadways and transit are built.

If Option A is constructed — the one with five general purpose lanes and an express lane in each direction — the study predicts travel times of 28 minutes during morning rush hours and 30 minutes in the evening.

If UDOT settles on Option B — with the reversible express lanes in the middle — the study predicts travel times of 21 minutes in the morning peak and 22 minutes in the evening.

Critics counter that over time the widening simply would encourage more car travel on the freeway, creating more congestion.

What does SLC’s mayor think?

Mendenhall said she understands the need to move commuters effectively, but she worries about what communities could lose.

“Highways and rail corridors that were built in generations past have divided our city and prevented prosperity from being able to take place in almost half of our city,” Salt Lake City’s mayor said. “So the perpetuation and the literal expansion of that division with a widening project that contemplates the elimination of homes of west-side residents is wholly unacceptable to me.”

All of this comes at a time when the city is seeking federal grants to remove barriers and reconnect east- and west-side communities.

For Mendenhall, fast-growing Utah is at a crossroads: Continue to fund more automobiles or take “a more appropriate” path by boosting public transit.

“I believe that we should be making those transitions right now,” she said, “and that they must be led by the state.”

Who would be most affected?

(Rick Egan | The Salt Lake Tribune) Homes border both sides of Interstate 15 in Woods Cross, on Thursday, Jan. 5, 2023. The state is proposing to widen the freeway between Salt Lake City and Farmington.

Pocock did not specify which neighborhoods would be most impacted or how many residents could be displaced. But in northern Salt Lake City, the neighborhoods nearest I-15 include Guadalupe, Poplar Grove, Fairpark and Rose Park. In southern Davis County, homes in Woods Cross are closest to the proposed expansion.

Pocock said the project team will “refine the design and evaluate impacts” throughout 2023. In any scenario, she said, UDOT would work to minimize impacts by using existing rights of way where possible.

Why are west-side communities concerned?

West-side residents and businesses fear displacement, worsening air and heightened heat and noise pollution. Though they feel burned by previous government projects, they hope to work with UDOT on alternatives that align better with neighborhoods.

The Westside Coalition, for instance, desires a cleaner, more-connected transportation system that provides accessible, equitable and convenient options for Salt Lake City’s west side. It wants lower emissions, lower costs and higher public transit use.

“We recognize the disproportionate negative impacts the current transportation system has on Salt Lake city’s west-side communities,” said Blake Perez, first vice chair of the coalition, “and we value bringing a sustainable transportation network that connects our communities to each other, our city and region.”

What does the community like about the total plan?

Mendenhall and neighborhood groups like the inclusion of cycling and pedestrian east-west connectivity alternatives, in addition to north-south links.

“This is a proposal that includes more beneficial aspects than we have historically seen in Salt Lake City-adjacent UDOT projects on the I-15 corridor,” the mayor said. But “there’s no amount of other benefits that can balance out the trauma that the elimination of dozens of homes would create in the neighborhood.”

How can residents speak out?

The public comment period for the widening study is open through Friday, Jan. 13. Residents can comment directly on maps of the proposal, through a comment form, through email or by regular mail. Residents also can contact the project team after this week.

What’s next?

When the public comment period ends, the project team will compile all the remarks for review as UDOT screens the alternatives and the environmental impact draft, Pocock said. These comments will help refine further options and identify a preferred alternative by fall for additional public review.

UDOT will then conduct further analysis as needed to prepare the final environmental impact statement. At that point, UDOT will issue a decision on which I-15 design — if any — it will undertake. Once funding is in place, the final design and construction could begin.