davidzipper.bsky.social - Profile | ThreadSky | a Reddit-style client for Bluesky

The leaders of the former TRB committees focused on sustainability have put together this survey to gather input about possible paths forward. docs.google.com/forms/d/e/1F...

submitted 1 day ago • 0 comments

I’m convinced that kei trucks would sell like hotcakes if Americans could buy them easily and drive them legally. Government just needs to get out of the way.

submitted 1 day ago • 9 comments

My contribution to this week's free-fare discourse: Studies consistently show that eliminating transit fares does not reduce urban driving or pollution. On the other hand, providing faster and more frequent/abundant service can absolutely achieve those goals.

submitted 1 day ago • 6 comments

What a pathetic reason to remove a bike lane: “There’s very few people that are a fan of how those look aesthetically.” -- @ddotdc.bsky.social director Kershbaum A nearby resident put it nicely: “They are sacrificing safety for aesthetics.”

submitted 1 day ago • 2 comments

In recent years, USDOT has published many documents supporting automatic speed cameras, which consistently reduce crashes. Under Trump, those docs are being rescinded or removed from USDOT's website. Here's an example (rescinded May 25, apparently): highways.dot.gov/sites/fhwa.d...

submitted 1 day ago • 4 comments

That "empty" bus or bike lane is probably moving a lot more people than you think! usa.streetsblog.org/2025/06/11/e...

submitted 1 day ago • 1 comment

New Danish study concludes that traffic noise is killing people: "A 14.9 decibel increase in road traffic noise [outside the home] was associated ... with an 8.1% increased risk of all-cause mortality." Traffic noise was much deadlier than air pollution. pubmed.ncbi.nlm.nih.gov/40403531/

submitted 1 day ago • 10 comments

A book I'd like to read: The history of automobiles and violence, from exploding car bombs to pickups driven into parties and protests (perhaps with a postscript on torched Waymos).

submitted 2 days ago • 5 comments

Commuter benefits shape travel habits. New study finds Denverites are: 🔹 195% more likely to drive to work if they get free/subsidized parking 🔹 789% more likely to bike if secure bike parking is offered 🔹 56% more likely to use transit if they get a subsidized pass ascelibrary.org/doi/abs/10.1...

submitted 2 days ago • 3 comments

Urban life would be infinitely better if minicars replace goliath-like SUVs and pickups.

submitted 3 days ago • 12 comments

New study of active travel (biking/walking) & climate: "For each add'l mile of daily active travel, an individual’s GHG emissions from travel [fall] 48 % if trip lengths are allowed to change (w/a fixed number of daily trips), and by 51%with no constraint on daily trips." doi.org/10.1016/j.tr...

submitted 3 days ago • 0 comments

New NBER paper: Shifting from the gas tax to a vehicle-miles-traveled tax would disproportionately benefit rural/Republican parts of the US. Reasons: 🔹 Higher EV uptake on the coasts (EV owners don't pay gas tax) 🔹 Gas cars in urban/Dem areas get better gas mileage www.nber.org/system/files...

submitted 4 days ago • 3 comments

Just finished one of the best bike rides of my life: Gdańsk to Sopot, along the Baltic. What a fantastic coastal cycle way.

submitted 5 days ago • 5 comments

With the S90 discontinued, Volvo is the latest carmaker to stop selling sedans in the USA. www.caranddriver.com/news/a644437...

submitted 7 days ago • 1 comment

Guerrilla crosswalks drive city officials crazy, but they're a remarkably effective street safety tactic. Sympathetic media coverage is all but guaranteed -- esp when local leaders overreact.

submitted 8 days ago • 5 comments

If I'm being cynical, I'd wonder if Uber is reinventing the bus so it can benefit if transit deteriorates in big US cities (i.e., service cuts caused by budget deficits).

submitted 8 days ago • 6 comments

UPDATE: TRB has posted its new, shrunken committee structure. Beyond ignoring equity, it has nothing related to climate change or pollution. I guess they're now unrelated to transportation? nap.nationalacademies.org/resource/oth...

submitted 9 days ago • 3 comments

Something I learned today at Volvo's car safety center in Gothenburg, Sweden: Volvo runs certain crash tests with dummies not wearing seatbelts -- specifically to reflect conditions in the US.

submitted 9 days ago • 8 comments

Unsurprising but important finding: Neighborhoods easily traversed by bike or on foot have lower car ownership and less PM2.5 pollution. doi.org/10.1016/j.jt...

submitted 9 days ago • 1 comment

For decades, the US was the gold standard for car safety regs. Not anymore -- that title now belongs to Europe. In Bloomberg, global auto reg exec @davidjward.bsky.social and I discussed why cars have grown safer around the world – but not in the US.

submitted 10 days ago • 4 comments

Big changes underway at @trb.org, which has canceled numerous research projects exploring how race, gender, and poverty affect transportation. Hopefully "back to basics" doesn't mean "pavement and asphalt."

submitted 11 days ago • 1 comment

Ambling through Gothenburg, Sweden, it’s refreshing to be in a place that prioritizes comfortable seating in public spaces. So many enticing benches and chairs! Quite a contrast with US cities these days.

submitted 11 days ago • 5 comments

Protected bike lanes have a near-magical ability to produce cyclists. This new study of 28 US cities finds that census block groups w/protected bike lanes expanded bike commuting almost 2x faster than those w/standard bike lanes & >4x faster than those w/o new lanes. www.nature.com/articles/s44...

submitted 11 days ago • 16 comments

Design vehicles to fit cities. Don’t design cities to fit vehicles.

submitted 15 days ago • 6 comments

Instead of driving in central London for free, EV owners will get 25% off the city's congestion charge. That makes intuitive sense. Like all cars, EVs cause congestion and create tire pollution, but they don't emit harmful tailpipe emissions. EVs' negative externalities are lower than gas cars.

submitted 16 days ago • 3 comments

Vision Zero is the opposite of this

submitted 17 days ago • 1 comment

A few months ago, @wesmars.bsky.social half-jokingly proposed a study examining how NACTO conferences catalyze street upgrades in the cities that host them. Unrelatedly, @nacto.bsky.social's annual meeting in DC is 2 days away, and I'm currently admiring this brand new cycleway on Eckington Place.

submitted 18 days ago • 5 comments