Every busy road produces a cloud of pollution you can't see. Where you stand in it matters more than most people might realise.
Paris said au revoir to cars. Air pollution maps reveal a dramatic change.
Air pollution fell substantially as the city restricted car traffic and made way for parks and bike lanes.
Speedcam Anywhere
Vehicle exhaust emissions - CO2, PM2.5 and NOx - are highest during acceleration. Microplastic particulates from tire emissions are highest during braking, accelerating and cornering quickly. In urban areas, vehicles accelerate and decelerate repeatedly due to junctions and traffic. Allowing for the emissions when vehicles are accelerating and they typically have the lowest NOx and CO2 emissions, and the best mpg, when driven at maximum speeds of 15-20mph. Particulate Matter (PM2.5) from tyre wear and brake pad wear is a lot higher when decelerating from higher speeds, and also from cornering at higher speeds. Because of the extra emissions during acceleration, NOx and CO2 go up rapidly when driving at higher speeds in urban areas.
Urban congestion relief experiments through routing-app interventions
Traffic congestion remains a persistent challenge for urban mobility, increasing travel delays and elevating CO2 emissions. The widespread use of smartphones and GPS navigation creates new opportunities to mitigate congestion through routing optimizations in apps, yet real-world evidence for the effectiveness of such interventions is limited. Here we report large-scale empirical experiments evaluating routing-based traffic interventions on ~100 highly congested road segments across 10 major US cities. By rerouting a small share of Google Maps trips from targeted congested highway and arterial segments to less congested alternatives of equivalent road-classes with comparable travel times, we observe a city-average 2% increase in vehicle speeds on the intervened segments, along with improved travel times 0.7% and potential annual reductions exceeding 1,000 tons of CO2-equivalent emissions per city in the majority of studied locations. These findings provide evidence that marginal routing interventions involving a small proportion of vehicles can measurably enhance overall road network efficiency, offering a practical pathway to easing congestion and advancing urban sustainability.
Britain’s cars and SUVs are growing bigger – but there is a way to stop this deadly ‘carspreading’ | Christian Wolmar
Larger vehicles crowd our roads and are far more dangerous to pedestrians. Let’s curb them before they do even more damage, says says transport commentator Christian Wolmar
Aeropolis – Queering Air in Toxicpolluted Worlds
Check out Aeropolis – Queering Air in Toxicpolluted Worlds - How do we get to know air? <i>Aeropolis: Queering Air in Toxicpolluted Worlds</i> offers a speculative and interdisciplinary framework to reorient common understandings of air and air pollution as matter “out there.” <i>Aeropolis</i> contests regimes of managing air which ultimately operate toward upholding dominant modes of world-making that are dependent on forms of exclusion and inequity. Instead, <i>Aeropolis</i> proposes that air is thought of as a city, to center its social, cultural, political, ecological entanglements. Drawing upon feminist technoscience and queer ecological frameworks, <i>Aeropolis</i> moves away from solutions toward a methodology of “designing-thinking-making” that redirects and connects our understandings of air—as designers, as citizens—with ongoing struggles for just futures. <br /><br />Moving through a series of design interventions, histories of air, and theoretical coordinates, <i>Aeropolis</i> thinks with air across its many forms—through smog and dust, bodies and breath, pollen and weeds, and from urban design to geopolitics, polluted environments to open data, parks to aerial infrastructures. It insists that we acknowledge the diversity of air and its relation to humans, non-humans, and environments, both physically and affectively. That we become sensible to air by following its unruliness—by living, breathing, seeing, holding, touching, queering airs.<br /><br />With contributions from María Puig de la Bellacasa and Timothy K. Choy. by Nerea Calvillo on Bookshop.org UK!
Exploring the social life of urban spaces through AI
We analyze changes in pedestrian behavior over a 30-y period in four urban public spaces located in New York, Boston, and Philadelphia. Building on William Whyte’s observational work, which involved manual video analysis of pedestrian behaviors, we employ computer vision and deep learning techniques to examine video footage from 1979–80 and 2008–10. Our analysis measures changes in walking speed, lingering behavior, group sizes, and group formation. We find that the average walking speed has increased by 15%, while the time spent lingering in these spaces has halved across all locations. Although the percentage of pedestrians walking alone remained relatively stable (from 67% to 68%), the frequency of group encounters declined, indicating fewer interactions in public spaces. This shift suggests that urban residents are using streets as thoroughfares rather than as social spaces, which has important implications for the role of public spaces in fostering social engagement.
Designing a wayfinding concept for Vancouver's Skytrain system.
I wasn’t always a big fan of public transport.
Cycling Toward a Cooler Toronto | The Power of Bike Lanes
The Deadly Rise of Giant Trucks and S.U.V.s
The vehicles on American roads have grown larger — and they are killing thousands more pedestrians, a Times investigation found.
Air Pollution and the Public Health Costs of AI
A new study by Caltech and UC Riverside uncovers the hidden toll that AI exacts on health throughout its lifecycle, from chip manufacturing to data center operation.
What the Unfinished Saga of a Still-Not-Built Subway Exit Taught Me About Public Consultation | The Local
One community volunteer traces 20 years of botched communication, unanswered questions, and delays—and asks what public consultation is actually worth.
Curb cut effect
The curb cut effect is the phenomenon of disability-friendly features being used and appreciated by a larger group than the people they were designed for. The phenomenon is named for curb cuts – miniature ramps comprising parts of sidewalk – which were first made for wheelchair access in particular places, but were also welcomed by people pushing strollers, carts or luggage. Curb cuts are now ubiquitous and no longer widely recognized as a disability-accessibility feature. Another example is hearing people using television closed captioning.
Yohan on Twitter / X
For six months, Google Maps sent a slice of drivers in ten American cities down deliberately slower routes.About 30 seconds slower on average, and under 2% of trips were touched. The experiment ran on roughly 100 of the most congested road segments in each city, switching on… pic.twitter.com/5cshNdmWU2— Yohan (@yohaniddawela) August 28, 2026
The curb-cut effect
The curb-cut effect illustrates how when we design to benefit disadvantaged or vulnerable groups we end up helping society as a whole. Angela Glover Blackwell explains how campaigning by students with disabilities in Berkeley in the early 1970s led to adding curb cuts to the Berkeley sidewalks to make access easier for those in wheelchairs. Yet it wasn't just people in wheelchairs that it helped. Curb cuts also made life easier for people pushing children in strollers, people using trolleys for deliveries, people pulling a suitcase, those wheeling bikes or on skateboards, and it also helps save lives by guiding people to cross at safe locations. Another example is adding closed captioning to TV that helps anyone watch in a noisy bar, a waiting room, or watching an airline safety video. Or a classic example of universal design in the OXO Good Grips range originally made to be comfortable for holding a peeler even if you have arthritis. It's also a useful analogy for "how laws and programs designed to benefit vulnerable groups, such as the disabled or people of color, often end up benefiting all," (PolicyLink) whether that be increasing broadband access, improving public transport or taking cuts out of curbs. Here's a short, fun video of Gary Karp explaining the curb-cut effect. Thanks to my patron Quintin Balsdon for sharing it with me.
Keep coming back to the idea that—ideally—the Atmosphere ultimately wants to become something like a public utility. But obviously not an American public utility. But also not a European one, nor one belonging to any conventional state. A new type of thing entirely—a global public utility.
