Lessons in Freeway Widening

The lesson is simple: don't widen freeways if you want to reduce congestion and auto-dependence.

1 minute read

August 26, 2017, 7:00 AM PDT

By James Brasuell @CasualBrasuell


Joe Cortright offers a collection of case studies on the futility of highway widening projects.

Cortright is offering these lessons in opposition to a proposal "to spend upwards of a billion dollars on three freeway widening projects" in the region around Portland, Oregon.

According to Cortright, the idea of widening freeways to lessen congestion has been "thoroughly debunked." In fact, writes Cortright, "[e]conomists now talk about the 'Fundamental Law of Road Congestion'–each incremental increase in highway capacity generates a proportionate increase in traffic, with the effect that congestion quickly rebounds to previous levels–accompanied by more sprawl, longer trips and increased pollution."

As examples to counter the argument of Oregon's highway widening project proponents, Cortright lists Houston (specifically, the 23-lane Katy Freeway), Dallas (i.e., the decision to cancel the Trinity Parkway), Louisville (the infamous Spaghetti Junction and Ohio River Bridges Project completed earlier this year), and Rochester (which began removing the Inner Loop freeway in late 2016).

Wednesday, August 23, 2017 in City Observatory

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Get top-rated, practical training

Wastewater pouring out from a pipe.

Alabama: Trump Terminates Settlements for Black Communities Harmed By Raw Sewage

Trump deemed the landmark civil rights agreement “illegal DEI and environmental justice policy.”

April 13, 2025 - Inside Climate News

High-rise apartment buildings in Waikiki, Hawaii with steep green mountains in background.

Study: Maui’s Plan to Convert Vacation Rentals to Long-Term Housing Could Cause Nearly $1 Billion Economic Loss

The plan would reduce visitor accommodation by 25% resulting in 1,900 jobs lost.

April 6, 2025 - Honolulu Civil Beat

Blue and white Seattle Link light rail train exiting concrete Downtown Bellevue Tunnel in Bellevue, WA.

Why Should We Subsidize Public Transportation?

Many public transit agencies face financial stress due to rising costs, declining fare revenue, and declining subsidies. Transit advocates must provide a strong business case for increasing public transit funding.

April 7, 2025 - Todd Litman

Silhouette of man holding on to back of bicycle ridden by woman with Eiffel Tower in background.

Paris Bike Boom Leads to Steep Drop in Air Pollution

The French city’s air quality has improved dramatically in the past 20 years, coinciding with a growth in cycling.

April 14 - Momentum Magazine

Multifamily housing under construction.

Why Housing Costs More to Build in California Than in Texas

Hard costs like labor and materials combined with ‘soft’ costs such as permitting make building in the San Francisco Bay Area almost three times as costly as in Texas cities.

April 14 - San Francisco Chronicle

Western coyote looking at camera in grassy field.

San Diego County Sees a Rise in Urban Coyotes

San Diego County experiences a rise in urban coyotes, as sightings become prevalent throughout its urban neighbourhoods and surrounding areas.

April 14 - Fox 5