Purpose Hour · September 2026

The streets we have aren't accidents.
They're choices.

Guest Speaker: Wes Marshall, PhD, PE · Professor of Civil Engineering & Urban Planning, CU Denver · Author, Killed by a Traffic Engineer

Every road, intersection, and curb in your city was designed by someone, though probably not with you in mind. Join us for a conversation about the hidden assumptions baked into our infrastructure, the real costs of building cities around speed, and what's possible when communities start making different choices.

39,254
People killed on U.S. roads in 2024
7×
Higher U.S. road death rate vs. Sweden, Switzerland & UK
+161%
Increase in Colorado pedestrian fatalities over the last decade
75%
Of new vehicle sales are SUVs, pickups, or light trucks
The Safety Picture

Road Deaths in America: Why the U.S. Is an Outlier

Nearly 40,000 people are killed on U.S. roads every year. But the raw numbers only hint at the real problem: compared to every other wealthy nation, the U.S. is not just behind. It is in a category of its own.

39,254
People killed on U.S. roads in 2024[1]
7,080
Pedestrians killed in 2024 (18% of all crash fatalities)[2]
+72%
Increase in pedestrian deaths since their lowest point in 2009[2]
+48%
Rise in pedestrian deaths since 2014, nearly 7× faster than population growth[3]
7×
U.S. road death rates per capita are seven times higher than Sweden, Switzerland, and the United Kingdom. The gap is so large that the OECD now publishes international road safety data both with and without the U.S. to avoid skewing the averages.[4]

Between 2013 and 2022, overall U.S. road traffic death rates increased 22.5%. Over the same period, the other 27 high-income countries saw a median decrease of 19.4%.[5] We are moving in the wrong direction while the rest of the world improves.

25% of pedestrian deaths in 2024 involved hit-and-run crashes. 73% occurred between 6 p.m. and 6 a.m. Nearly two-thirds happened in locations without a sidewalk.[2] [3]

Close to Home

Colorado & Denver: The Trend Hits Home

+161%
Increase in Colorado pedestrian fatalities over the last decade[6]
120
Pedestrians killed in Colorado in 2024; up from 10% to 19% of all traffic deaths since 2002[7]
237
Colorado deaths from speeding in 2024, more than impaired driving (215) or unbuckled crashes (189)[8]
47%
Of all Colorado pedestrian fatalities in 2024 occurred in just 3 counties: Denver, Adams, and El Paso[7]

A pedestrian's risk of death when struck is 10% at 23 mph and 75% at 50 mph.[8] Speed isn't an accident. It's a product of how we design the road. Since 2016, pedestrian and bicyclist deaths in Colorado have increased 34% while passenger vehicle occupant deaths rose less than 3%.

The Arms Race on Our Streets

How Vehicles Got Bigger: What It's Costing Us

The vehicles on our roads aren't the same as they were 30 years ago. They are dramatically heavier, taller, and wider, and the physics of what happens when they hit a pedestrian has changed with them.

75%
Of new vehicle sales today are SUVs, pickups, or light trucks. In 2009, that share was 38%.[9]
+1,000 lbs
Average weight gain of U.S. passenger vehicles over 30 years (also 4" wider, 10" longer, 8" taller)[10]
+45%
More likely to cause a pedestrian fatality: vehicles with a hood above 40" vs. those below 30"[10]
+22%
Increase in pedestrian fatality risk for every 10 cm increase in a vehicle's front-end height[11]
~3,000
Estimated additional pedestrian deaths from 2016–2024 attributable specifically to the shift toward higher-hood vehicles, a number researchers consider likely conservative.[12]

The share of pedestrian fatalities involving trucks, vans, and SUVs has risen from 22% to 44% since the mid-1980s. Pickup trucks are now 32% heavier than in 1990. Some full-size pickups have front ends up to 55 inches high, creating blind zones especially dangerous for children and wheelchair users.[13]

Between 2000 and 2019, an estimated 8,100 additional lives were lost in crashes with pickups and SUVs that would likely have survived had those crashes involved standard passenger cars.[11]

Beyond the Crash

The Environmental Footprint of How We Build Cities

28%
Of total U.S. greenhouse gas emissions come from transportation, the single largest sector[14]
5.5%
Of all U.S. land covered by parking lots (larger than Rhode Island and Delaware combined)[15]
26%
Median share of central city land dedicated to parking in large U.S. cities; some exceed 30–50%[16]
2 billion
Estimated U.S. parking spaces, roughly 7 for every registered vehicle[16]
10 trillion
Gallons of untreated stormwater runoff generated every year in the U.S. by impervious surfaces such as roads and parking lots, carrying oil, heavy metals, and pollutants into waterways.[17]

Car-dependent sprawl contributes to higher air pollution, greater heat exposure, and worsening stormwater flooding. All that pavement absorbs heat from the sun and intensifies the urban heat island effect, driving surface temperatures significantly higher in densely paved city centers.[18] [16]

The global SUV fleet, if ranked among countries, would be the world's fifth largest CO₂ emitter. SUVs burn on average 20% more fuel than standard passenger cars.[11] In Los Angeles, parking occupies more land than housing. That land can't absorb rain, can't support trees, and can't be anything else.[19]

Read the Book

Killed by a Traffic Engineer

Shattering the Delusion that Science Underlies our Transportation System

The research behind tonight's conversation. Marshall pulls back the curtain on a century of road design built on unproven assumptions, and makes the case that safer, more human streets are possible once we choose to demand them.

Buy from Bookshop.org Princeton University Press