Commentary: I-270 Expansion Will Harm Latino Communities, Increase Air Pollution, and Accelerate Climate Change

I-270 map
Source: CDOT,
Allen Cowgill headshot
Allen Cowgill (Photo by Adam Bove)

This guest commentary is by Allen Cowgill, a Denver advocate focused on safer streets and sustainable transportation. He is a member of the Denver Bicycle Lobby and is on Twitter at @AllenCowgill.

The Colorado Department of Transportation (CDOT) is planning to increase lanes for cars and trucks on I-270 and says this project is about “improvements and safety.” In reality, it will increase pollution in neighborhoods inhabited mostly by people of color and could accelerate climate change by encouraging more people to drive.

CDOT could rapidly increase safety by improving deadly state highways: Federal, Colfax, Colorado, Sheridan, Alameda, and other urban arterials are the deadliest streets in Denver. This isn’t just a Denver problem. From 2009 to 2016, U.S. arterial roads designed to move large volumes of traffic quickly saw a 67% increase in pedestrian fatalities.

What if we don’t change I-270? CDOT’s traffic projections (PPTX file) say travel times would increase by one to six minutes by the year 2040. The budget for this project, $400 million, seems like a ridiculous amount to lower travel times by just a few minutes. That money could be better spent elsewhere, like on Bus Rapid Transit on Federal or Colfax or on finishing the B-Line rail to Boulder.

We know that new lanes bring more traffic. With induced demand, it is only a matter of time before traffic volume returns. A California Air Resources Board report found that every 1 percent increase in urban highway capacity leads to a roughly 1 percent increase in vehicle travel. TREX, the Denver area’s massive interstate expansion on I-25, was a $1.2 billion project that took six years to complete, and it relieved congestion for only five years before traffic returned to pre-construction levels.

SWEEP chart 2000-2013 shows TREX relieved traffic congestion for only five years before traffic returned to pre-construction levels
Source: Southwest Energy Efficiency Project,

Motor vehicles cause 50-90% of air pollution in urban areas. Increasing the number of cars on the road will increase air pollution and poison in our air. Although calls for increasing the number of electric vehicles are laudable for harm reduction, electric vehicles don’t solve the problem: non-exhaust emissions from brakes, tires, and other parts account for 60-73% of particulate matter pollution from cars. CDOT and other advocates for highway expansion have argued that less traffic congestion – faster moving vehicles – means less air pollution. This is simply not true: research has shown that offsets in congestion are negated by new traffic volume due to induced demand. The largest source of greenhouse gas emissions is from cars, trucks, and other vehicles, so highway expansions that put more vehicles on the road can accelerate climate change.

Many studies have shown negative health impacts and shorter life expectancy associated with living near highways. Living near major roads or highways is linked to higher incidence of multiple diseases including dementia, Parkinson’s disease, Alzheimer’s disease, and multiple sclerosis. Recent research from the Colorado Department of Public Health and Environment found a potential link between air pollution and COVID deaths.

People who live near this highway expansion will be disproportionately impacted, and those people are predominantly people of color. The students at Adams City High School, which serves neighborhoods surrounding I-270, are 87% Latino. The systematic racism that planned these highways through communities of color in the past is still alive and well as it expands highways through these communities today. The I-270 expansion will continue to burden communities already disproportionately impacted by poor air quality. (See: Suncor refinery)

Expanding I-270 is not an improvement. It will kill more community members, mostly Latinos, over time with poisoned air and is effectively arson in the fight against climate change. I-270 is not the only planned expansion that will impact communities of color in Denver. A Central I-70 expansion is under construction in Elyria-Swansea, and CDOT is planning to expand Santa Fe Drive. CDOT also plans to add lanes to I-25 through Denver, which will impact Denver’s poorest neighborhood, Sun Valley.

These highway expansions are at odds with climate change mitigation, equity, and clean air. They are a waste of taxpayer dollars and will do little to reduce long-term congestion.

Editor’s note: You can share your thoughts about I-270 with CDOT at

Do you have an idea for a guest commentary? Please fill out this form.

Support the nonprofit mission of Streetsblog Denver. Give $5 per month.



This Interstate 70 viaduct cuts through the Denver neighborhoods of Elyria, Swansea, and Globeville. It will be torn down expanded to a 14-lane sunken freeway. Photo: CDOT.

Report: Expanding I-70 Is out of Step With Polis’ Goals

A new report calls for the removal of America's 10 worst urban highways, including Interstate 70 through Denver’s mostly Latino neighborhoods of Elyria, Swansea, and Globeville. Local activists see the report as a chance to renew their calls to stop the project — especially after electing Gov. Polis, who campaigned on cutting vehicle emissions and increasing mass transit.