Seth LaJeunesse

@sethlaj.bsky.social

Transportation systems researcher. The reason cities keep failing cyclists and pedestrians isn’t engineering. It’s deeper. It’s coalition politics and cultural signaling. That’s what I write about.

The use of biological metaphors in traffic engineering is irritating af. “Arterials?” As in arteries? Really? If we must use biological metaphors, arterials should be rebranded as “lacerationals” on the face of our communities.

Milwaukee's mayor protecting "decades of established traffic patterns" from a boulevard that would free 16 acres and add $16M/year in tax revenue. Which patterns count as the unquestioned default, and which have to prove themselves? usa.streetsblog.org/2026/07/23/m...

Milwaukee Mayor Abandons Highway Teardown To Calm Irrational Fears Of Driver Class — Streetsblog USA

Mayor Cavalier Johnson has set aside years of findings that highway removals help revitalize Rust Belt downtowns for the 21st century.

usa.streetsblog.org

Rebuilding the BQE costs 3x what removing it and building light rail would. Off-Ramp NYC ran the numbers. Street-level transit beats elevated highways every time: cheaper, pays for itself in tax and farebox revenue. We need to make highway removal a thing. www.nydailynews.com/2026/07/21/t...

The BQE’s broken math (and opportunity)

For decades, the city Department of Transportation has asked, “How should we rebuild the crumbling triple cantilever of the Brooklyn-Queens Expressway (BQE)?”

nydailynews.com

Surface parking has cratered 50% of Carrboro, NC’s downtown. Ergo, I walk 50% more steps than I would have if 0% of downtown was cratered by parking. Turns out surface parking is a public health win! 🏅

This is Greenville, SC’s Saturday farmers’ market. This is Downtown. This is Main Street. Nary a car passing through or edging into a parking spot in sight. This shouldn’t be exceptional.

Looking northward up Main Street in downtown Greenville, SC. A farmers’ market with many a stand and nary a car (save a police car blocking car access).

Note the crossing signs on the side of this Main Street in Carrboro, NC. Also note the lack of a marked crosswalk. Question: when only ~20% of drivers yield to peds WITH a marked crosswalk at this location, what % are likely to yield WITHOUT a marked crosswalk?

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Worth remembering that a lot of people do not “prefer” to drive despite their driving behavior. No, these people drive because all alternatives have been made objectively unsafe, uncomfortable, impractical, or all three. Read: “revealed preference” is bs.

If we are serious about seeing more than 1-3% cycling mode share, we need to rally behind “minimum viable network density” policies. No more of these separated bike lane islands.

A teenager can hear his classmates playing baseball from his stoop. The road between them has no crosswalk, no signal, trucks doing 40. He sometimes makes it across. When he does, someone tells him to get in left field. New essay ↓

New essay Thursday: a girl who lives beside a highway, who has woods behind her house she has stopped going to, who wonders what the birds are saying and has no way to get close enough to find out. The argument isn't about mobility. It's about who the infrastructure won't let her become.