David M Levinson ⁂'s Avatar

David M Levinson ⁂

@transportist.org

‪https://www.transportist.org @transportist@mastodon.social‬ @transportist.mastodon.social.ap.brid.gy Trnsprtst. Rogue Planner. Refreshingly Unromantic. So F*ing Lucid. fRSN. 2%. Research: #Access, #TransportEconomics, #NetworkEvolution, #Traffic.

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Latest posts by David M Levinson ⁂ @transportist.org

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E-Bikes: Convenience, Annoyance, or Menace? Are E-Bikes a Convenience, an Annoyance, or a Menace? Yes, yes they are. The answer depends on your point-of-view. If you are a e-bike user, such as a commuter, recreational traveler, or deliverista, it must be a convenience (otherwise why do it). If you are the consumer of warmed over restaurant meals delivered by e-bikes, you probably agree. But, if you are not, the answer is less clear.E-bike (used for deliveries on Train (T8 line) inconveniencing those who want to exit train. That big battery there is not overly reassuring either. It’s an ORCA bike and certified, but nevertheless. As a pedestrian, I find e-bikes being ridden on the footpaths (or “shared paths”) at a minimum an annoyance, even if the rider is legal and under 16, which in my experience they mostly are. I find the collection of shared e-bikes abandoned on footpaths even more of an annoyance due to its frequency. A collection of shared e-bikes at the top of the hill in my suburb. Clearly the user is happy to walk downhill to the station, but takes the e-bike uphill. This is easily fixed with prices (free trips to return bikes to train stations), but the world’s best and brightest cannot be fussed to actually solve that in their app, and so periodically send a truck around to collect these bikes and reposition them at the train station. Progress! I am not alone in not being thrilled with all these new e-bikes, one only needs to see the Letters to the Editor of the local St. George Leader for examples of e-bikes being ridden in what-to-fore were pedestrian spaces to see the issue writ large. * Close call with e-bike for Cronulla man recovering from shoulder surgery * Stabbing victim hospitalised in Bondi Beach after alleged teen machete attack triggered by e-bike argument: The argument is believed to have been sparked by e-bikes. I see drivers complaining about e-bikes darting in and out-of-traffic. One only needs to read the articles (and comments) in the Daily Telegraph1 or other local media to see that lots of people feel that way. The youth have organised themselves for fun days out, which not everyone appreciates. * Hoons in death-defying stunts on Sydney motorway - A group of unregistered dirtbike riders have been caught undertaking death-defying stunts on one of Sydney’s busiest freeways, popping wheelies and weaving between motorists. * Popular Sydney golf course vandalised by e-bikes I think something needs to be done about the growing number of e-bikes, especially the high powered ones, on the roads and especially footpaths. I think the number of deaths and injuries per km driven on e-bikes puts them in the same arena as automobiles in terms of safety implications, and dismissing this by just looking at the numerator (fatalities), without also considering the denominator (exposure, such as km ridden) is misleading. Unfortunately, we don’t actually know the denominator, though we can surmise it is still much lower, though rising fast. An obvious, first-best solution that most professionals and bicycle advocates support is to build more bike lanes and lower speed limits on local roads. I agree with this. I think mandatory training and licensure is probably safer than its absence, and enforcement of traffic rules is even more critical. People with drivers licenses should not be immune from e-bike licensure, driving a car and an e-bike are not the same thing. The NSW government is doing something, perhaps it should do more. * Regulation on e-bike power is underway: Under the standard, e-bikes must have a maximum power output of 250 watts and power assistance must cut out at 25km/hr. * Age limits are probably coming in too. * Illegal e-bikes will be seized and crushed. Another obvious solution is to take parking spaces from cars for the corralled storage of shared bikes off the footpaths, with geofenced enforcement on the part of the bikeshare operators. Sadly, after some 8 years of shared bikes in the City of Sydney, this has yet to happen. E-bikes have popped up in Bayside Council in recent months. No serious effort has been made to corral them in Bayside either. A third obvious solution is to give the youth some place to act out that doesn’t annoy the oldth. I agree with this, but I believe the whole point of most youth acting out is to annoy the oldth, so good luck with that. HOWEVER, we have not actually built a comprehensive bike lane network in Sydney. The all-powerful bike lobby has yet to deliver for us. This leaves us in the realm of the second best: in the absence of bike lanes, how do we regulate this new vehicle type for the good of all in the here and now. When cars came in more than 100 years ago, we regulated pedestrian movement in the name of safety, but in reality for the convenience of cars. This greatly reduced pedestrian access. We are at risk of doing the same today, converting pedestrian-only footpaths to shared paths so that fast electrically powered bicycles driven by adults are legal in even more pedestrian spaces, discouraging more people from walking. I hope we can do better. FYI * BicycleNSW position * WalkSydney Position FIN 1 Yes, I know. Nevertheless, the readers and commentators are people who vote. Read more

E-Bikes: Convenience, Annoyance, or Menace?

09.03.2026 15:04 👍 1 🔁 1 💬 0 📌 0
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Multiple cars damaged as carnage strikes Melbourne finale | Supercars A spin sends championship leader Broc Feeney into the path of Cooper Murray in a wild start to Race 7

This sounds great, let's definitely bring this to Sydney. www.supercars.com/news/superca...

08.03.2026 22:00 👍 0 🔁 0 💬 1 📌 0
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Two Cities, Two Times Check the date! No fooling today. In May 1965 Saint Paul actually did do daylight saving time differently than Minneapolis. At the time the Twin Cities’ discordant time change was the best example …

Semi annual posting about one of the comical moments in Minnesota's history of fragmented governance. This is history, but it's also allegory for problems today
streets.mn/2014/04/03/t...

08.03.2026 13:58 👍 5 🔁 1 💬 0 📌 0
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War With Iran Could Lead to More Coal — and More Solar The race to find cheap energy is on.

" #Ethiopia banned the import of internal combustion vehicles due to worries about the high costs of oil imports and fuel subsidies. #EVs make up some 8% of the cars on the road in the East African country, up from virtually zero a few years ago."

How many more countries will now follow suit?

08.03.2026 01:03 👍 4 🔁 2 💬 1 📌 0

Wikipedia reports Saudi Arabia at 33.7M, Yemen at 32.8M. The GDP per capita is obviously very different. The UN has Yemen at about 40M population.un.org/wpp/assets/F...

06.03.2026 22:11 👍 1 🔁 0 💬 0 📌 0

TIL, according to some sources, Yemen has more people than Saudi Arabia.

06.03.2026 21:55 👍 1 🔁 0 💬 1 📌 0

What, they want a casino is Astana?

06.03.2026 19:49 👍 0 🔁 0 💬 1 📌 0

Shhh

06.03.2026 17:27 👍 0 🔁 0 💬 0 📌 0

Surprised more people don't believe their deity (deities) has forsaken them.

05.03.2026 21:10 👍 0 🔁 0 💬 0 📌 0
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Scenes of BikeSharing in Sydney People parking shared bikes in Sydney, both individual riders, and the organisations (Lime, HelloRide, and Ario) don’t generally seem to care about people walking, and will just inconvenience…

The companies don’t care, the users don’t care, the city doesn’t enforce transportist.org/2025/09/19/s...

05.03.2026 18:21 👍 1 🔁 0 💬 1 📌 0
Luke Skywalker drinks Blue Milk on Tatooine

Luke Skywalker drinks Blue Milk on Tatooine

05.03.2026 07:24 👍 0 🔁 0 💬 0 📌 0
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Network Origin-Demand Estimation using Percolation Recently published: * Levinson, David (2026) Network Origin-Demand Estimation using Percolation (NODE). Findings. [doi] This paper presents a network origin--destination estimation (NODE) method for trip distribution that applies a percolation-like graph search to allocate trips from origins to destinations. Expanding in cost order from each origin, NODE matches productions to available attractions, depleting destination capacities as they are filled. Multiple origins compete for the same destinations; later arrivals may be diverted to more distant alternatives. The result is an OD matrix spatially constrained by network topology and impedance, without a global gravity function or logit structure. NODE can replicate gravity results in some settings, but departs in cases of destination capacity constraints, network bottlenecks, and heterogeneous acceptance, offering a simple, network-aware alternative to conventional models.

ICYMI: Network Origin-Demand Estimation using Percolation

05.03.2026 02:43 👍 1 🔁 0 💬 0 📌 0

University students with event outside my office window playing The Police and Duran Duran. It's like I never graduated, universities remain in a 1980s time bubble.

04.03.2026 23:32 👍 1 🔁 0 💬 1 📌 0

Once again, I think 13 Justices is the wrong way to do it. It appears like "packing" the court. If you go with *100* Justices, who handle cases on panels of 9, you fix the underlying problem of a small number of justices. www.techdirt.com/2026/01/16/t...

04.03.2026 07:01 👍 361 🔁 91 💬 31 📌 3

So
Much
Less
Expensive

04.03.2026 05:48 👍 0 🔁 0 💬 0 📌 0
Better Streets Submission for Walking and Cycling Improvements between South Eveleigh and Waterloo Metro (Henderson Road) - Jake Coppinger I wrote this submission on behalf of Better Streets for the proposed Walking and Cycling Improvements between South Eveleigh and Waterloo Metro (Henderson Road).

Submissions for the Henderson Road Cycleway close today 5pm!

5 min advocacy - please drop an email tosydneyyoursay@cityofsydney.nsw.gov.au and say you support the Henderson Road Cycleway!

jakecoppinger.com/2026/03/bett...

04.03.2026 01:31 👍 1 🔁 1 💬 0 📌 0

Nuclear powered HSR. Flooded tunnels that submarines operate in.

04.03.2026 01:43 👍 2 🔁 0 💬 1 📌 0

We're going to see a lot more really cool AI-assisted proofs.

04.03.2026 00:06 👍 9 🔁 3 💬 1 📌 1

Be the change, write the story. The US was moving in the right direction for a while. It just didn't stay the course. Noting a lot of the "shortage" problem was self-inflicted, not allowing oil markets to move freely in the US, which deregulation fixed (creating different problems for another day).

04.03.2026 00:41 👍 3 🔁 0 💬 0 📌 0
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Waymo Says It Has Nothing to Say After Its Self-Driving Taxi Blocked an Ambulance Responding to a Mass Shooting "Come on! Go!"

“The Google-owned Waymo told outlets that it would not be providing a statement.”

04.03.2026 00:04 👍 89 🔁 37 💬 3 📌 10

Perhaps the first, I doubt the latter.

03.03.2026 23:38 👍 0 🔁 0 💬 0 📌 0
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15-Minute Cities – How Urban Design Entered the Culture War Spotify video

15-minute cities : How Urban Design Entered the Culture Wars

[The whole conspiracy is bonkers, but planners need to get better at branding]

open.spotify.com/episode/0Vhx...

03.03.2026 21:38 👍 0 🔁 0 💬 0 📌 0
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How Seoul Metro Installed Platform Screen Doors Everywhere The political history of a safety equipment

new S(ubstack)-Bahn post: 20 years ago, Seoul was haggling over whether to install platform screen doors at its Metro stations. many called it a waste and an impossibility.

now it’s at all Metro stations across South Korea. how did this transformation happen?

www.substack-bahn.net/p/how-seoul-...

06.09.2025 15:05 👍 109 🔁 32 💬 6 📌 16
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Network Origin-Demand Estimation using Percolation Recently published: Levinson, David (2026) Network Origin-Demand Estimation using Percolation (NODE). Findings. [doi] This paper presents a network origin--destination estimation (NODE) method for trip distribution that applies a percolation-like graph search to allocate trips from origins to destinations. Expanding in cost order from each origin, NODE matches productions to available attractions, depleting destination capacities as they are filled.

Network Origin-Demand Estimation using Percolation

Recently published: Levinson, David (2026) Network Origin-Demand Estimation using Percolation (NODE). Findings. [doi] This paper presents a network origin--destination estimation (NODE) method for trip distribution that applies a percolation-like…

03.03.2026 20:17 👍 0 🔁 0 💬 0 📌 0

Weirdly still flying over war zone between Afghanistan and Pakistan

03.03.2026 18:50 👍 1 🔁 0 💬 1 📌 0
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Judge Lewis Liman (brother of Doug Liman) has ruled that the federal government can‘t unilaterally end congestion pricing, giving the MTA yet another court win on congestion pricing

03.03.2026 16:51 👍 512 🔁 66 💬 5 📌 11
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Currently reading the 1959 Congressional hearing where Bill Vickrey — a future Nobel Prize winner — made the first public case for congestion pricing.

Vickrey: "One of the advantages of this type of charge is that you discourage the peak use at the same time that you encourage the nonpeak use."

03.03.2026 16:30 👍 61 🔁 12 💬 3 📌 2

But everything in academia is laggy, so we will have the deficits before the cutbacks. Undergraduate education is a different matter, and that is already in trouble with demographics and changing value of University education.

03.03.2026 16:39 👍 0 🔁 0 💬 0 📌 0

Being able to do research for nearly free (with AIs) breaks the whole post war “research university“ model. Students won’t be needed at first in lots of fields. Sponsors will pull funding support from expensive suppliers (labor-intensive) where substitutions are possible. Fewer PhDs, less overhead.

03.03.2026 16:36 👍 0 🔁 0 💬 1 📌 0

So if the sponsor is the private sector you get one kind of research, if it is the public, something else. The best sponsors from the POV of the academic just give money essentially string-free. The University does a little bit of that, but the pressure is to get outside $.

03.03.2026 16:33 👍 0 🔁 0 💬 1 📌 0