Matthew Raifman, PhD🚶‍♂️🚲🚇🛴

Thoughts on transport & road safety & climate / photog / Transportation Researcher at U.C. Berkeley.

[Matthew Raifman, PhD🚶‍♂️🚲🚇🛴 @MatthewRaifman]

Last week, Census released 2021 data giving us our first look at the spatial distribution of the transition to working from home. A tale of two Americas emerges. Those who could adjust to work from home, and those who could not.
A quick deep viz dive into the data...🧵
#wfh

[Matthew Raifman, PhD🚶‍♂️🚲🚇🛴 @MatthewRaifman]

@DCTrikeMom @LaneSquattersDC @bikelane Reprehensible and made even more so by the fact that you kid was in front. I can’t imagine explaining that situation to our four year old but I fear that I may need to someday. Supporting you from afar!

[Matthew Raifman, PhD🚶‍♂️🚲🚇🛴 @MatthewRaifman]

@alpert So bring AV back into that world and we’d be in a better place. No distracted driving or speeding, but a deconflicted intersection where ped has priority and crosswalk to themself.

[Matthew Raifman, PhD🚶‍♂️🚲🚇🛴 @MatthewRaifman]

With AVs, we have two competing forces at play: 1) AVs can be programmed to be safer drivers than humans; 2) when cars and humans mix, we have a recipe for collisions and, worse, fatalities. If we want safe roads, with AVs or not, we need to de-conflict the road network. (1/x)

[San Francisco Chronicle @sfchronicle]

JUST IN: The California DMV has suspended Cruise from operating its driverless taxis in San Francisco, effective immediately. https://t.co/1tHKzD66Pw

[Matthew Raifman, PhD🚶‍♂️🚲🚇🛴 @MatthewRaifman]

@alpert Take the ped crossing:
- always signal priority to ped
- no car turn on red
- red light camera enforcement
- shorter crossings

So yes, still ped crossing but ped priority & ped and car do not share same space at same time.

[Matthew Raifman, PhD🚶‍♂️🚲🚇🛴 @MatthewRaifman]

@alpert Oh yes, I definitely don’t want to suggest that we should be building tunnels for cars though understand how that might come off that way. I’m for tactical urbanist low-cost separation of cars from less/cyclists.

[Matthew Raifman, PhD🚶‍♂️🚲🚇🛴 @MatthewRaifman]

@alpert Personally, I think we need to stop thinking about AVs as a monolith.

Yes, we might have safety concerns about human/AV interaction on city roads, but there are applications when there is limited conflict (eg BRT, trucking). Labor policy issues but the problem isn’t tech there.

[Matthew Raifman, PhD🚶‍♂️🚲🚇🛴 @MatthewRaifman]

@alpert There is also temporal aspect: safer now, or safer later when tech matured?

1st: eventually AVs may be able to detect human behavior well.

2nd: much of the challenge is this transition time when AVs & human share the road. As balance shifts to AVs, they become inherently safer

[Matthew Raifman, PhD🚶‍♂️🚲🚇🛴 @MatthewRaifman]

@alpert I hear you. What about flipping it around and thinking about fencing off cars to prevent conflict. Say what we might about the mismanagement of the Big Dig in Boston, but moving those cars underground and topping it with a walkable park was a move in the right direction I think

[Matthew Raifman, PhD🚶‍♂️🚲🚇🛴 @MatthewRaifman]

@Karminker Yes, in the US it’s called a 7Eleven

[Matthew Raifman, PhD🚶‍♂️🚲🚇🛴 @MatthewRaifman]

If we want a safe network, if we want walking and bike commuting (and also btw if we want AVs), we need to move to a network that deconflicts users.

#AutonomousVehicles #roadsafety #urbanplanning #transportation #streetdesign

[Matthew Raifman, PhD🚶‍♂️🚲🚇🛴 @MatthewRaifman]

Ultimately, AVs are a technology that is actually safer than the human alternative but is limited (at least today) by a road network that contains operational conflicts that require human interaction. The same conflicts that drive traffic fatalities north of 40k a year in the USA

[Carlos Gould @gould_cf]

Out today in @Nature, we show that PM2.5 from wildfires has reversed, eroded, or stagnated broader improvements in total PM2.5 levels in 3/4 of contiguous US states. Led by superstar Marissa Childs and @MarshallBBurke with excellent team

[Matthew Raifman, PhD🚶‍♂️🚲🚇🛴 @MatthewRaifman]

@DavidZipper What the what? Sometimes… 🤦‍♂️