David Zipper
@davidzipper.bsky.social
Senior Fellow @ MIT Mobility Initiative & Contributing Writer @ Vox, focused on transport, cities and tech. Words in Atlantic, CityLab, WaPo, etc. https://linktr.ee/davidzipper
Newsletter, speaking and advisory work: http://davidzipper.com
Newsletter, speaking and advisory work: http://davidzipper.com
Pinned
David Zipper
@davidzipper.bsky.social
· Jul 15
Look Both Ways Podcast: Episode 1
YouTube video by Look Both Ways with David & Wes
www.youtube.com
A bit of news:
@wesmars.bsky.social & I are launching Look Both Ways, a new podcast where we’ll debate everything transportation – from street design to robotaxis to fare-free transit.
First episode will be recorded live on Thurs, July 17th at 6p ET.
Join us then (and subscribe) ⤵️
🧵
@wesmars.bsky.social & I are launching Look Both Ways, a new podcast where we’ll debate everything transportation – from street design to robotaxis to fare-free transit.
First episode will be recorded live on Thurs, July 17th at 6p ET.
Join us then (and subscribe) ⤵️
🧵
The BBC investigates British car bloat and "Chelsea tractors":
"The standard minimum width of an on-street parking space is 1.8m, [but] more than half of the 100 top-selling cars in the UK were fractionally wider than this."
"The standard minimum width of an on-street parking space is 1.8m, [but] more than half of the 100 top-selling cars in the UK were fractionally wider than this."
'Carspreading’ is on the rise - not everyone is happy - BBC News
In the UK and across Europe, cars are becoming longer, wider and heavier.
www.bbc.com
December 6, 2025 at 1:43 PM
The BBC investigates British car bloat and "Chelsea tractors":
"The standard minimum width of an on-street parking space is 1.8m, [but] more than half of the 100 top-selling cars in the UK were fractionally wider than this."
"The standard minimum width of an on-street parking space is 1.8m, [but] more than half of the 100 top-selling cars in the UK were fractionally wider than this."
I call bullshit.
See thread below.
See thread below.
December 5, 2025 at 4:33 PM
I call bullshit.
See thread below.
See thread below.
In @bloomberg.com, I argued that traffic lights are a street safety solution that’s hiding in plain sight
At minimal cost, cities can adjust them to slow speeders, protect pedestrians, and avoid dangerous turns.
Pushback from drivers is rare; they may not even notice.
At minimal cost, cities can adjust them to slow speeders, protect pedestrians, and avoid dangerous turns.
Pushback from drivers is rare; they may not even notice.
A Bright Idea for Road Safety: Traffic Light Timing
Cities that adjust stoplight cycles to emphasize safety can curb dangerous driving without racking up big costs or triggering pushback from motorists.
www.bloomberg.com
December 5, 2025 at 1:53 PM
In @bloomberg.com, I argued that traffic lights are a street safety solution that’s hiding in plain sight
At minimal cost, cities can adjust them to slow speeders, protect pedestrians, and avoid dangerous turns.
Pushback from drivers is rare; they may not even notice.
At minimal cost, cities can adjust them to slow speeders, protect pedestrians, and avoid dangerous turns.
Pushback from drivers is rare; they may not even notice.
Reposted by David Zipper
New episode is up!
Is the e-bike industry in trouble? Why is Boston fighting Waymo? What are David's and Wes's all-time favorite car trips?
To find out, click below (or listen on your favorite podcast platform)
Is the e-bike industry in trouble? Why is Boston fighting Waymo? What are David's and Wes's all-time favorite car trips?
To find out, click below (or listen on your favorite podcast platform)
Look Both Ways #11: Memorable Road Trips, Waymo Restrictions, eBike Bankruptcy? & New Access Words
YouTube video by Look Both Ways with David & Wes
www.youtube.com
December 5, 2025 at 2:15 AM
New episode is up!
Is the e-bike industry in trouble? Why is Boston fighting Waymo? What are David's and Wes's all-time favorite car trips?
To find out, click below (or listen on your favorite podcast platform)
Is the e-bike industry in trouble? Why is Boston fighting Waymo? What are David's and Wes's all-time favorite car trips?
To find out, click below (or listen on your favorite podcast platform)
"I don't think there's a CEO on this planet that cares more about safety than me."
- Elon Musk
- Elon Musk
Musk says new Tesla software allows texting and driving, which is illegal in most states | TechCrunch
Texting while driving is banned in nearly every state, even with the use of advanced driver-assistance systems like Tesla's Full Self-Driving (Supervised) software.
techcrunch.com
December 5, 2025 at 12:04 AM
"I don't think there's a CEO on this planet that cares more about safety than me."
- Elon Musk
- Elon Musk
Reposted by David Zipper
America: where road safety is so motorist-centered that small cars are too dangerous to allow on the market!
Unlike Europe and Asia, NHTSA & Congress have failed to create a regulatory category for minicars. Because they flunk US safety rules for full-sized cars, they’re effectively illegal to sell.
Only “collectable” minicars cars 25+ years old can be legally sold (and they’re quite popular).
Only “collectable” minicars cars 25+ years old can be legally sold (and they’re quite popular).
What Do US Vehicle Regulators Have Against Tiny Cars?
Super-small urban vehicles have found a place in European and Asian cities. But in the US, federal and state rulemakers seem determined to keep minicars at bay.
www.bloomberg.com
December 4, 2025 at 3:34 PM
America: where road safety is so motorist-centered that small cars are too dangerous to allow on the market!
I’ve been writing about kei cars and minicars for years, and I’d be thrilled to see them legalized in the US. But I suspect this story/White House announcement is less than meets the eye.
Legalizing minicars is a heavy regulatory/political lift, not a “flip the switch” kind of change.
Quick 🧵
Legalizing minicars is a heavy regulatory/political lift, not a “flip the switch” kind of change.
Quick 🧵
Trump Wants Asia’s ‘Cute’ Kei Cars to be Made and Sold in US
President Donald Trump, apparently enamored by the pint-size kei cars he saw during his recent trip to Japan, has paved the way for them to be made and sold in the US, despite concerns they’re too sma...
www.bloomberg.com
December 4, 2025 at 1:08 PM
I’ve been writing about kei cars and minicars for years, and I’d be thrilled to see them legalized in the US. But I suspect this story/White House announcement is less than meets the eye.
Legalizing minicars is a heavy regulatory/political lift, not a “flip the switch” kind of change.
Quick 🧵
Legalizing minicars is a heavy regulatory/political lift, not a “flip the switch” kind of change.
Quick 🧵
Among the many reasons this is very bad:
The environmental advocacy/foundation world was *just starting* to push for less driving, not just less gas-powered driving.
I fear they'll now revert to promoting EVs -- full stop.
The environmental advocacy/foundation world was *just starting* to push for less driving, not just less gas-powered driving.
I fear they'll now revert to promoting EVs -- full stop.
Trump Returns to Gasoline as Fuel of Choice for Cars, Gutting Biden’s Climate Policy
www.nytimes.com
December 3, 2025 at 10:00 PM
Among the many reasons this is very bad:
The environmental advocacy/foundation world was *just starting* to push for less driving, not just less gas-powered driving.
I fear they'll now revert to promoting EVs -- full stop.
The environmental advocacy/foundation world was *just starting* to push for less driving, not just less gas-powered driving.
I fear they'll now revert to promoting EVs -- full stop.
Free business idea:
Coffee shop where people joining a Zoom call are promptly told to step outside.
Coffee shop where people joining a Zoom call are promptly told to step outside.
December 3, 2025 at 6:24 PM
Free business idea:
Coffee shop where people joining a Zoom call are promptly told to step outside.
Coffee shop where people joining a Zoom call are promptly told to step outside.
Reposted by David Zipper
this should just immediately write you a ticket when you turn it on
Love to share the road with cars programmed to blast past speed limits
Tesla brings back 'Mad Max' 'Full Self-Driving' mode that ignores speed limits
Tesla has brought back its 'Mad Max' mode for 'Full Self-Driving (Supervised) that ignores speed limits amid several investigations.
electrek.co
December 3, 2025 at 4:04 PM
this should just immediately write you a ticket when you turn it on
Reposted by David Zipper
Don't worry, your city wrung their hands a lot over where to draw the geofence lines so those dangerous e-scooters would be limited to 15 mph vs turned off altogether
Love to share the road with cars programmed to blast past speed limits
Tesla brings back 'Mad Max' 'Full Self-Driving' mode that ignores speed limits
Tesla has brought back its 'Mad Max' mode for 'Full Self-Driving (Supervised) that ignores speed limits amid several investigations.
electrek.co
December 3, 2025 at 3:49 PM
Don't worry, your city wrung their hands a lot over where to draw the geofence lines so those dangerous e-scooters would be limited to 15 mph vs turned off altogether
Love to share the road with cars programmed to blast past speed limits
Tesla brings back 'Mad Max' 'Full Self-Driving' mode that ignores speed limits
Tesla has brought back its 'Mad Max' mode for 'Full Self-Driving (Supervised) that ignores speed limits amid several investigations.
electrek.co
December 3, 2025 at 3:33 PM
Love to share the road with cars programmed to blast past speed limits
Salute to Toronto for this pivot:
Ontario premier Doug Ford banned Toronto from building new bike infrastructure that replaces car lanes.
Toronto's response: Narrow but retain existing car lanes, freeing enough space to keep installing bike lanes. (Better yet, narrower traffic lanes are safer.)
Ontario premier Doug Ford banned Toronto from building new bike infrastructure that replaces car lanes.
Toronto's response: Narrow but retain existing car lanes, freeing enough space to keep installing bike lanes. (Better yet, narrower traffic lanes are safer.)
'It's a win-win': How Toronto is planning 20km of new bike lanes without defying Ford
The City of Toronto is also planning $30-million worth of infrastructure upgrades, including bike lanes, cycle tracks, and trails.
toronto.citynews.ca
December 3, 2025 at 1:16 PM
Salute to Toronto for this pivot:
Ontario premier Doug Ford banned Toronto from building new bike infrastructure that replaces car lanes.
Toronto's response: Narrow but retain existing car lanes, freeing enough space to keep installing bike lanes. (Better yet, narrower traffic lanes are safer.)
Ontario premier Doug Ford banned Toronto from building new bike infrastructure that replaces car lanes.
Toronto's response: Narrow but retain existing car lanes, freeing enough space to keep installing bike lanes. (Better yet, narrower traffic lanes are safer.)
DC folks: I'm giving a keynote at @waba.org's District Bike Summit this Sunday in Adams Morgan.
My topic: How cyclists should think about autonomous vehicles
Free to attend if you pre-register: waba.org/event/dbs-20...
My topic: How cyclists should think about autonomous vehicles
Free to attend if you pre-register: waba.org/event/dbs-20...
December 3, 2025 at 12:42 PM
DC folks: I'm giving a keynote at @waba.org's District Bike Summit this Sunday in Adams Morgan.
My topic: How cyclists should think about autonomous vehicles
Free to attend if you pre-register: waba.org/event/dbs-20...
My topic: How cyclists should think about autonomous vehicles
Free to attend if you pre-register: waba.org/event/dbs-20...
Reposted by David Zipper
Fair questions... but now let me proceed to only somewhat vaguely, kind of answer one of them.
December 3, 2025 at 12:22 AM
Fair questions... but now let me proceed to only somewhat vaguely, kind of answer one of them.
This op-ed is truly terrible.
A few obvious failures:
🔹 Why are Waymo's self-reported data treated as fact?
🔹 Why does the writer ignore myriad ways to save lives that are cheaper, more reliable, and quicker than waiting for AVs?
🔹 Why doesn't he mention he's a VC partner?
A few obvious failures:
🔹 Why are Waymo's self-reported data treated as fact?
🔹 Why does the writer ignore myriad ways to save lives that are cheaper, more reliable, and quicker than waiting for AVs?
🔹 Why doesn't he mention he's a VC partner?
“There’s a public health imperative to quickly expand the adoption of autonomous vehicles.”
Would the author say the same about building bike lanes? Installing automatic traffic cameras? Requiring Intelligent Speed Assist?
All of those are proven to save lives — and at a fraction of AVs' cost.
Would the author say the same about building bike lanes? Installing automatic traffic cameras? Requiring Intelligent Speed Assist?
All of those are proven to save lives — and at a fraction of AVs' cost.
Opinion | Don’t Fear Self-Driving Cars. They Save Lives.
www.nytimes.com
December 2, 2025 at 3:05 PM
This op-ed is truly terrible.
A few obvious failures:
🔹 Why are Waymo's self-reported data treated as fact?
🔹 Why does the writer ignore myriad ways to save lives that are cheaper, more reliable, and quicker than waiting for AVs?
🔹 Why doesn't he mention he's a VC partner?
A few obvious failures:
🔹 Why are Waymo's self-reported data treated as fact?
🔹 Why does the writer ignore myriad ways to save lives that are cheaper, more reliable, and quicker than waiting for AVs?
🔹 Why doesn't he mention he's a VC partner?
“There’s a public health imperative to quickly expand the adoption of autonomous vehicles.”
Would the author say the same about building bike lanes? Installing automatic traffic cameras? Requiring Intelligent Speed Assist?
All of those are proven to save lives — and at a fraction of AVs' cost.
Would the author say the same about building bike lanes? Installing automatic traffic cameras? Requiring Intelligent Speed Assist?
All of those are proven to save lives — and at a fraction of AVs' cost.
Opinion | Don’t Fear Self-Driving Cars. They Save Lives.
www.nytimes.com
December 2, 2025 at 2:46 PM
“There’s a public health imperative to quickly expand the adoption of autonomous vehicles.”
Would the author say the same about building bike lanes? Installing automatic traffic cameras? Requiring Intelligent Speed Assist?
All of those are proven to save lives — and at a fraction of AVs' cost.
Would the author say the same about building bike lanes? Installing automatic traffic cameras? Requiring Intelligent Speed Assist?
All of those are proven to save lives — and at a fraction of AVs' cost.
Reposted by David Zipper
New livestream recording this Thursday at 6p Eastern!
On the agenda:
🔹 Boston's looming battle over robotaxis
🔹 Is the e-bike industry in trouble?
🔹 Making "transportation access" make sense
Join @davidzipper.bsky.social & @wesmars.bsky.social on YouTube live via link below
On the agenda:
🔹 Boston's looming battle over robotaxis
🔹 Is the e-bike industry in trouble?
🔹 Making "transportation access" make sense
Join @davidzipper.bsky.social & @wesmars.bsky.social on YouTube live via link below
Look Both Ways LIVE with David & Wes: Episode 11
YouTube video by Look Both Ways with David & Wes
www.youtube.com
December 2, 2025 at 2:06 PM
New livestream recording this Thursday at 6p Eastern!
On the agenda:
🔹 Boston's looming battle over robotaxis
🔹 Is the e-bike industry in trouble?
🔹 Making "transportation access" make sense
Join @davidzipper.bsky.social & @wesmars.bsky.social on YouTube live via link below
On the agenda:
🔹 Boston's looming battle over robotaxis
🔹 Is the e-bike industry in trouble?
🔹 Making "transportation access" make sense
Join @davidzipper.bsky.social & @wesmars.bsky.social on YouTube live via link below
Better idea IMO: Spend a couple hundred bucks on a decent coffee roaster, and you'll never need to buy craft coffee again (nor will you want to).
Until I got a roaster a few months ago, I had no idea how delicious coffee could be. I was living in Plato's cave.
Until I got a roaster a few months ago, I had no idea how delicious coffee could be. I was living in Plato's cave.
Coffee subscriptions offer their steepest discounts around Cyber Monday and Black Friday. Here are the best deals WIRED has found. www.wired.com/story/best-c...
Craft Coffee Costs Too Much. But It's Cheaper on Cyber Monday
Coffee subscriptions offer their steepest discounts around Cyber Monday and Black Friday. Here are the best deals WIRED has found.
www.wired.com
December 1, 2025 at 8:22 PM
Better idea IMO: Spend a couple hundred bucks on a decent coffee roaster, and you'll never need to buy craft coffee again (nor will you want to).
Until I got a roaster a few months ago, I had no idea how delicious coffee could be. I was living in Plato's cave.
Until I got a roaster a few months ago, I had no idea how delicious coffee could be. I was living in Plato's cave.
This Friday at noon ET, I'll join an MIT Mobility Initiative webinar to discuss my research exploring the politics of urban speed reduction.
(TL;DR: Tactics like speed humps, automatic cameras, and road diets are more popular than many think)
Open to the public: mit.zoom.us/meeting/regi...
(TL;DR: Tactics like speed humps, automatic cameras, and road diets are more popular than many think)
Open to the public: mit.zoom.us/meeting/regi...
December 1, 2025 at 7:48 PM
This Friday at noon ET, I'll join an MIT Mobility Initiative webinar to discuss my research exploring the politics of urban speed reduction.
(TL;DR: Tactics like speed humps, automatic cameras, and road diets are more popular than many think)
Open to the public: mit.zoom.us/meeting/regi...
(TL;DR: Tactics like speed humps, automatic cameras, and road diets are more popular than many think)
Open to the public: mit.zoom.us/meeting/regi...
Paint is not infrastructure.
"Vancouver’s painted lanes were associated with higher cyclist KSI; Calgary’s cycle tracks with fewer KSI."
KSI = Killed or seriously injured
doi.org/10.1016/j.aa...
"Vancouver’s painted lanes were associated with higher cyclist KSI; Calgary’s cycle tracks with fewer KSI."
KSI = Killed or seriously injured
doi.org/10.1016/j.aa...
November 30, 2025 at 9:10 PM
Paint is not infrastructure.
"Vancouver’s painted lanes were associated with higher cyclist KSI; Calgary’s cycle tracks with fewer KSI."
KSI = Killed or seriously injured
doi.org/10.1016/j.aa...
"Vancouver’s painted lanes were associated with higher cyclist KSI; Calgary’s cycle tracks with fewer KSI."
KSI = Killed or seriously injured
doi.org/10.1016/j.aa...
Wise policymakers would seize this opportunity to increase the federal gas tax for the first time since 1993, encouraging EVs while fortifying the Highway Trust Fund.
Zero chance that will happen, but it should.
Zero chance that will happen, but it should.
November 29, 2025 at 11:31 PM
Wise policymakers would seize this opportunity to increase the federal gas tax for the first time since 1993, encouraging EVs while fortifying the Highway Trust Fund.
Zero chance that will happen, but it should.
Zero chance that will happen, but it should.
“It’s time to demand automakers return to providing vehicles appropriate for jam-packed cities.”
Shawn Micallef: This truck ad shows why Toronto needs smaller vehicles — if only the carmakers wanted to sell them
A car comically overloaded with plywood? It’s a good ad for a pickup — but also a sign of the incredible amount of money, weight and energy being wasted on
www.thestar.com
November 29, 2025 at 9:23 PM
“It’s time to demand automakers return to providing vehicles appropriate for jam-packed cities.”
Really can't overstate how problematic robotaxis become at scale:
"Urban traffic is constrained by the fact that getting around by car either requires (expensively) paying someone else to drive or (inconveniently) driving oneself. Without such constraints the result could be brutal gridlock."
"Urban traffic is constrained by the fact that getting around by car either requires (expensively) paying someone else to drive or (inconveniently) driving oneself. Without such constraints the result could be brutal gridlock."
Self-driving cars will transform urban economies
A robotaxi boom is coming. The impacts might be broader than you expect
www.economist.com
November 27, 2025 at 8:04 PM
Really can't overstate how problematic robotaxis become at scale:
"Urban traffic is constrained by the fact that getting around by car either requires (expensively) paying someone else to drive or (inconveniently) driving oneself. Without such constraints the result could be brutal gridlock."
"Urban traffic is constrained by the fact that getting around by car either requires (expensively) paying someone else to drive or (inconveniently) driving oneself. Without such constraints the result could be brutal gridlock."
Reposted by David Zipper
A very good piece on bike share and tourism.
As a Lyft Pink subscriber I get member pricing on bike share in NYC and Chicago, so I mostly got around by bike when I visited. Boston, on the other hand, charges high daily and per-trip rates to tourists; so I took a lot of ride-hails instead.
As a Lyft Pink subscriber I get member pricing on bike share in NYC and Chicago, so I mostly got around by bike when I visited. Boston, on the other hand, charges high daily and per-trip rates to tourists; so I took a lot of ride-hails instead.
$10.69 for a 15-minute ride?
For visitors, public bikeshare often feels like a ripoff.
In CityLab, I explored why.
For visitors, public bikeshare often feels like a ripoff.
In CityLab, I explored why.
Bikeshare Shouldn’t Kick Tourists to the Curb
Barcelona’s bikeshare program excludes non-Spanish visitors. Other cities charge tourists much higher fees to rent two-wheelers. Which policy makes more sense?
www.bloomberg.com
November 25, 2025 at 9:35 PM
A very good piece on bike share and tourism.
As a Lyft Pink subscriber I get member pricing on bike share in NYC and Chicago, so I mostly got around by bike when I visited. Boston, on the other hand, charges high daily and per-trip rates to tourists; so I took a lot of ride-hails instead.
As a Lyft Pink subscriber I get member pricing on bike share in NYC and Chicago, so I mostly got around by bike when I visited. Boston, on the other hand, charges high daily and per-trip rates to tourists; so I took a lot of ride-hails instead.