Between the daily headlines shouting out Millennial takeovers and Denver’s housing shortage, you’ve probably heard about the Colorado Department of Transportation (CDOT) plan to widen I-70 by four lanes between I-25 and Tower Road. At $1.7 billion and about 12 miles long, the project is hard to miss. It’s massive in cost and scope. It will cost some people their homes — CDOT will fund their relocation — and affect Denver’s air quality, too.

But right now, the I-70 widening is treading water while CDOT officials figure out if it passes muster with the Federal Highway Administration (FHWA).

So what’s the holdup? CDOT needs more time to estimate how much particulate matter and carbon monoxide will pollute Denver’s air, as a result of expanding I-70, through 2040. The agency only included projections through 2035 in its environmental impact statement for FHWA, which has to clear the project before CDOT can hire contractors and begin construction. Public comments convinced the agency to revisit the emissions issue, which will delay the project up to four months, says Rebecca White, a CDOT spokesperson.

“At this point we know that 2040 would probably have higher emission levels than 2035, so we need to look at 2040 if we have the capability of doing that,” White says. She says she expects the projected emissions to clear national standards set by the Clean Air Act in order for construction to begin in early 2018.

After a planning process that began more than 13 years ago, a months-long delay is like a millisecond, White says. Still, the delay has given advocates against the project pause.

Some Denver residents, backed by the Sierra Club’s Rocky Mountain Chapter, targeted the project with a federal lawsuit in March 2016 over its impact to Denver’s air quality in a neighborhood that sees worse pollution and higher asthma rates than neighborhoods further from the highway. Attorney Bob Yuhnke thinks the delay is because both the state and the feds have cold feet.

“[Governor John Hickenlooper] hired a new executive director at CDOT whose primary mission is to get I-70 done,” Yuhnke says. “The mayor wants it done. Most of the city council wants it done. So the fact that it’s not happening is not politically driven. It is driven by the litigation risk that they face.”

Yuhnke, a longtime environmental attorney, says he’s never seen a record of decision delayed like this “and that tells me that we have raised some serious issues that they were not prepared to deal with, and that they have to find a solution for.”

Halting a project of this size based on federal air quality regulations would be a first, Yuhnke says, and could set a precedent that spells trouble for federally funded highway projects for years to come.

Highway Walls

Several forward-thinking cities, including Austin, have damned highway expansions as a relapse into 20th-century urban planning that forever scarred immigrant and low-income neighborhoods. Hulking, grade-separated roads both divided and constrained urban neighborhoods like Denver’s Globeville and Elyria-Swansea in order to zoom people and goods through them.

If the I-70 expansion does move forward, it diverges from the path recently heralded by the U.S. Department of Transportation, led by Secretary Anthony Foxx, which would fund much of Denver’s widening.

Foxx himself grew up walled in by a highway’s concrete and cars in Charlotte. He recently guided cities to mend those scars in a major speech. “By the time we reach 2013, there’s almost no denying this direct correlation between those low-income areas and the highway system,” Foxx said at the Center for American Progress in March 2016. “The people in my community at the time these decisions were made were actually not invisible. It is just that at a certain stage in our history, they didn’t matter. If we want a society in which everyone has a real shot no matter where they come from, then it’s imperative that we acknowledge that these divisions, past and present, still exist.”

Foxx would not take a position on the I-70 project when he visited Denver in May. The widening will claim 56 homes and 18 businesses in mostly non-white, low-income neighborhoods — though the design does include a four-acre park over the newly sunken highway.

The Mousewheel of “Induced Demand”

It’s not always easy to see how spending billions of dollars on bigger roads jibes with Denver leaders’ stated goals for the future.

In 2013, Mayor Michael Hancock’s administration committed to “provide mobility options (transit, carpooling, biking, walking) that reduce commuting travel in Denver done in single-occupant vehicles to no more than 60 percent of all trips” by 2020. So, three years. But that figure was at 73 percent in 2015 — up 3.4  percent from 2014 — according to American Community Survey data.

When CDOT widened I-25, it took less than five years for traffic to reach pre-construction levels, according to a report by the Southwestern Energy Efficiency Project and the Colorado Public Interest Research Group (CoPIRG). The more room you make for vehicles, the more convenient it is to drive, so more people drive. Transportation planners call it “induced demand.” In Houston, it took six years for the widest highway in the world to fill back up with cars after some segments were widened to 23 lanes.

Roads are important, says CoPIRG Director Danny Katz, but scarce transportation funding should be used for “fixing and maintaining what we have” and creating a buffet of transportation options, including high-capacity transit.

“The I-70 corridor is one corridor where we do have some options, like the A Line,” Katz says. “What if it was free? What kind of an impact could that have on that corridor to enable us to not widen the highway, but instead provide affordable, convenient options, so people don’t have to drive.”

Yuhnke suggests spending “even a chunk” of the highway money to build a rapid bus network to connect all the neighborhoods not served by RTD’s rail expansion “so that we can actually reduce further pollution and advance the governor’s climate agenda.”

Intentions and Outcomes

The bureaucratic delay on the I-70 project hasn’t stopped the Denver Department of Public Works from trying to mitigate current and future congestion. The department just received a $6 million federal grant to create “freight efficiency corridors” by incentivizing companies to transport goods during off-peak travel hours. The grant includes a partnership with Waze, a mapping app, in which city traffic officials can disperse and collect real time information, and communicate with drivers.

Public Works is also working with CDOT to pilot “smart city” technology on I-70 and city streets “so we can be more dynamic and perhaps predictive in our signal operations,” says Director of Transportation and Mobility Crissy Fanganello.

Fanganello doesn’t have any say over I-70’s expansion, but knows it will change the transportation network for years to come, and she’ll have to be ready. To “dial up” values like walkability, which highway-ravaged neighborhoods lost during last century’s interstate buildout, other values will have to be dialed down.

“How, really, are we going to move more people in this constrained system, and what does that look like?” Fanganello says. “You know, everyone loves a bike lane until it affects their parking. Everyone thinks bus rapid transit is OK, until they realize you’re gonna take a general traffic lane. In a lot of ways, I-70 is not different. How do we understand the infrastructure and use the investment to actually meet the outcomes that we are intending to meet? But I don’t know that we as a community are always clear about what those outcomes are.”

Note: The I-70 expansion, as planned, is estimated to cost $1.7 billion, but CDOT only has identified funding for $1.2 billion, for phase one.