Universities select students, enrol them in classes, and certify the result, and confuse success at one activity with success at the others.

Selecting

Do we really think firms hire Harvard graduates because of what they were taught in Cambridge rather than who was selected in the first place? Harvard has already done a screening exercise for the employer. So long as a student can comply sufficiently with the university system, they are awarded a degree four years later. That degree carries the screening information even before we ask what happened in the classroom.

Universities and their associated admission processes are designed to sort prospective students into the best institution they can attain, subject to constraints of money, geography, admissions, and everything else. Then we rank the institutions using the outcomes of the people they selected.

A university can admit excellent students, who applied because of the university’s historically accumulated reputation, and graduate excellent students without having added very much.

Another can do a great deal for students who arrived less prepared and still look worse in the rankings.

Teaching

We can document that teaching took place. Classes were taught, assignments marked, rubrics applied, student surveys completed.1 There are Canvas engagement snapshots and peer observation notes. The file is complete.

Accreditation adds its own bureaucracy. We map assessments to learning outcomes, learning outcomes to graduate attributes, and assemble reports showing that the mappings have been reviewed. External reviewers examine the evidence. We demonstrate that we have processes for assuring ourselves that students have learned.

But an accredited course is not an independently examined graduate. Reviewing our assessments and marking practices still leaves the question of what graduates retain and can do without our prompts, rubrics, and rehearsed problems. The rubric may focus the student and the instructor on more specific knowledge at the expense of the general, or other specific knowledge not previously disentangled. By over-reliance on standards, we are treating education as if it were an industrial process, rather than a bespoke set of interactions that shape individual brains.

How much of the effort spent documenting that we assess learning could go into finding out what actually survives? We have made the assurance of learning into a substantial administrative activity. We should demand evidence that the assurance itself is worth the work, we do more now than 30 years ago, but can’t show graduates are better.

What did the students learn? What do graduates still know a few years later? Can they think better? These are the actual outcomes. They are not explicitly assessed. We may know where our graduates are. We already follow graduates into employment and track their salaries. We can ask about retained learning too. A salary and an understanding of a subject are different outcomes. The rest, our assessment of teaching, is paperwork about the process.

Certifying

A passing grade records achievement at the time of assessment. Those assessments are developed by the instructors themselves. An assessment does not establish that the knowledge was retained, or that the student can use it when the problem looks different. We make a considerable leap from completing the course to having acquired an education.

A rank records relative position, not an absolute standard. Somebody has to finish last. They need not be incompetent. Somebody has to finish first. They need not be competent.

Would you cross a bridge designed by the best student in a class where nobody understood structural mechanics?

The student wants to pass. The university wants the student to remain enrolled and complete. Our officials celebrate higher passing rates. Society wants the qualification to mean something.

When those interests diverge, whom do we serve: the customer, or the society subsidising the education and relying on its standards? This arrangement deserves more scrutiny than it gets.

Assess the achievement

Society should demand the separation of teaching from at least some of the assessment.

An independent assessment should ask whether the student can do what the qualification promises. Where they learned it should be a different question. If they learned from books, work, or another teacher, the knowledge is still knowledge, the capability exists.

This would also make the teaching itself easier to evaluate. Establish what students can do when they enter. Examine what they can do when upon exit. Follow up with a sample later and find out what survived.

For example, give them a problem they have not rehearsed and require them to explain it orally. An engineer should be able to reason through a design, identify what could go wrong, and defend the assumptions. We should be interested in the student’s understanding as well as the submitted document.2

The problem is that accreditation locks in old knowledge. New material must displace the old, not just accumulate. What makes a good transport engineer in 2026 should be different from what was standard when I was a student.

But independent of the specific curriculum, the point here is to establish what the test-taker knows and can do. Comparing that with what they knew on entry gives us evidence about what the education added. We should not assume the conclusion before doing the assessment. That would not survive the most basic academic peer review.

And the lectures?

If you had asked me in the 1450s about Gutenberg’s printing press, I would have thought it sufficient to decimate traditional higher education. Once you know how to read, why do you need lectures?

Demonstrations, discussions, tutoring, laboratory experiments, sure. But lectures? The oral tradition should have fallen by the wayside centuries ago.

Will AI finally do what the printing press did not? I mean, who knows? Are universities on a long slow decline, or are we operating in the world of cartoon physics?

Read more

Thesis Title: Detecting Dangerous Driving

Lead Supervisor: Professor David Levinson.

Abstract:

Risky driving behaviors contribute to road crashes, which impose major social and economic burdens. To tackle this phenomenon, this thesis develops two main ideas. First, it examines what factors influence the choice to drive after visiting alcohol-serving establishments (ASEs), where driving may be riskier due to impairment, late-night travel, fatigue, and reduced attention. This then motivates the rest of the thesis, which uses computer vision to detect and measure dangerous and unusual driving behaviors from traffic-camera footage, linking this early-stage risk context to objective indicators of near-crashes and crash risk.

In this thesis, we begin by examining the factors influencing the choice to drive from alcohol-serving establishments (ASEs) using the Victorian Integrated Survey of Travel and Activity (VISTA) dataset. The thesis then shows how computer vision and existing roadside traffic cameras can be used to: (1) detect dangerous driving behaviors such as speeding, short headway, lane violations, and aggressive driving; (2) compare road safety indicators under different weather conditions; and (3) detect unusual driving behaviors such as slipping, running off the road, passing on the shoulder, and abrupt stopping.

The results of the first part of the thesis show that people tended to drive for longer ASEs and walk for shorter ones. Going home made driving more likely, while going to other social activities did not show the same pattern. Men were more likely than women to drive after visiting ASEs. In addition, short travel distances (<1 km) and 3–4 hour activity durations were associated with a greater chance of switching from driving to other travel modes for ASE trips.

With regard to the application of computer vision, first, data extracted from 258 hours of traffic-camera footage in Minnesota are combined with crash records from 2016–2022. The relationship between dangerous driving behavior indicators (DDBIs) and the number of events where time-to-collision (TTC) falls below two seconds (NTTC2) is examined using an Ordinary Least Squares model. A Negative Binomial Regression model then links NTTC2 to crash frequency, and Structural Equation Modeling is used to describe the broader links between driving behavior, near-crash risk, and crashes. Results show that short headway, speeding, and aggressive driving increase NTTC2, and higher NTTC2 is associated with more crashes.

Second, surrogate safety measures (modified TTC, short headway, and lane violations) are compared across weather conditions using 268 hours of traffic-camera footage collected in Minnesota. To better capture changing road-surface conditions, the road–tire friction coefficient is incorporated into the TTC and safe-gap calculations, providing a more realistic safety assessment for dry, wet, and snowy roads. The findings provide consistent evidence that adverse weather increases the risk of surrogate crashes, helping to clarify previously mixed results in the literature.

Third, this thesis develops a heuristic, trajectory-based algorithm to automatically detect unusual driving behaviors using vehicle trajectories extracted from traffic-camera video. The algorithm is applied to 360 hours of footage from nine highway segments in Minnesota under clear, rainy, and snowy conditions, covering 1,120,751 vehicles. Fifteen types of UDBs are identified, including running off the road, slipping in snow, abrupt pull-overs, and police-related stops. The results confirm that the proposed algorithm can effectively detect unusual driving behaviors from large-scale traffic-camera data.

By analyzing road traffic video footage, we demonstrated the potential of computer vision to detect dangerous and unusual driving behavior. Our findings provide a practical foundation for real-time traffic surveillance and proactive road safety monitoring.

The first publications from the Dissertation are:

• SHAER, A., FIELBAUM, A., LEVINSON, D. (2026) Detecting Dangerous Driving Via Computer Vision: Linking Video-Based Indicators To Road Crashes. Journal of Transportation Safety and Security. [doi]

• SHAER, A., FIELBAUM, A., LEVINSON, D. (2024) Choosing To Drive From Alcohol Serving Establishments. Traffic Injury Prevention. 25(8), 1013-1022. [doi]

• Wang, Z., Ramezani, M. and Levinson, D. (2027) A communication-free decentralised two-dimensional trajectory controller for autonomous vehicles on a lane-free road: A level-k game approach. Transportation Research Part C: Emerging Technologies, Volume 194, January 2027, 105959. [doi]

This paper proposes a two-dimensional trajectory controller (2DTC) for autonomous vehicles (AVs) operating on a lane-free freeway. Without relying on inter-vehicle communication, each AV independently determines its acceleration and steering in real time. The 2DTC is formulated as a receding-horizon optimal control problem (OCP) with nonlinear dynamics, costs, and constraints. The OCP is discretized and solved using the continuation/GMRES method to obtain the optimal control values. Strategic interactions between AVs are captured through a level-k game theory model. The performance of the 2DTC is evaluated through both microscopic and macroscopic analyses. Microscopic simulations show that the generated trajectories are smooth and compliant with constraints, while macroscopic measures are used to construct fundamental diagrams, demonstrating capacity levels exceeding those typically reported for human-driven freeway traffic. Further experiments show that higher reasoning depth yields reductions in travel time, while increased vehicle size heterogeneity improves traffic efficiency by enabling more compact packing in lane-free flow. In addition, more homogeneous vehicle speeds tend to result in higher average speed, thereby improving efficiency. Comparisons with a similarly defined lane-based controller reveal that lane-free traffic is less efficient when vehicle sizes are uniform but becomes more efficient once size heterogeneity exceeds a critical threshold of roughly 22%.

Keywords:

Automated vehicle, Trajectory planning, Model predictive control, Nonlinear control, Game theory

• Mann, I. and Levinson, D. M. (2026) Fare enough: A quantitative spatial transport model for transit pricing. Transportation Research Part A: Policy and Practice, Volume 214, December 2026, 105237. [doi]

Standard transport appraisal treats fare regulation in isolation, ignoring how price signals reshape urban geography. We bridge regulatory practice and quantitative spatial economics by constructing a Quantitative Spatial Transport Model (QSTM) for Greater Sydney, endogenising household and firm locations in response to transport shocks. Our framework extends the canonical quantitative spatial model by endogenising commuter mode choice and internalising network externalities through road congestion and the Mohring effect. Evaluating three public transport pricing interventions, including zero-fare, flat-fare, and fare-cap policies, we find that free transit is welfare-suboptimal, driven largely by operator revenue losses. In our setting, distance-based fares provide a spatial price signal that helps internalise resource costs and discourage sprawl, a signal that uniform flat fares mute. The model demonstrates that allocative efficiency requires a higher user contribution, revealing that weekly fare caps function as implicit subsidies for long-distance commuters. Higher fares trigger a spatial reorganisation where residents centralise to minimise commuting costs and firms decentralise to access labour. Ultimately, efficient distance-based pricing promotes a compact residential form, encourages polycentric employment, and reduces operator resource costs.

Keywords:

Quantitative spatial models, Transport appraisal, Fare regulation, Agglomeration economies, Spatial general equilibrium, Urban economics

Posts

Publications

Pointers

• Your Regular Reminder

  • Car ramming in Normandy, France

• AVs

  • Waymo involved in fatal crash, but probably not the cause

  • Waymo lifts the lid on the ‘brain’ powering its robotaxis

• EVs

  • The state of battery-swapping EVs

• Walking

  • India’s Supreme Court declared in June that the right to walk safely on designated footpaths was a fundamental right.

• Transit

  • Why transit suddenly costs so much. - by Reece Martin

• Social Media

  • Mastodon: Transport Starter Kit 1, Starter Kit 2

Press

• Plans for high-speed rail line from Sydney to Newcastle just got one step closer

Sydney University transport professor David Levinson warned against people getting excited that the plans would result in a high-speed train line being constructed.

“They still have to come up with the money to build the thing. Someone has to fund $90 billion,” he said. “Until they show the money it’s not real.”

My general practitioner (GP) was concerned about my cholesterol1 levels, particularly given my family history. He had prescribed statins. With more than 1/4 of adults in my age group on statins, this was not uncommon.

Statins did not go well. I am apparently statin-intolerant.2 They made me feel like I had a constant fever: muscle aches, tired, and what I imagine being 20 years older feels like, what the doctor called myalgia. We tried another statin to no avail.

So, rather than continuing to speculate about how much of a problem my cholesterol actually was, my GP sent me for a CT scan3 to look for calcification in the coronary arteries.

The result on that front was mild calcification on left anterior descending (calcium score of 50) (65th percentile).4 So the cholesterol level was not a major problem, all things considered.

The scan did, however, find something else.

There’s a little black spot on my heart today

The CT showed a suspected cardiac myxoma in my left atrium.

What’s a cardiac myxoma?5

It is a rare,6 usually benign tumour that grows inside the heart. “Benign” is doing a fair bit of work in that sentence. It means the tumour isn’t cancerous. It does not mean that having a large tumour floating around inside your heart is a good idea, or even not harmful.

An echocardiogram corroborated.

Mine was initially estimated at about 50 mm across and occupied a substantial fraction of my left atrium. This provides definitive evidence that I do, in fact, have a heart. It also suggests that mine is considerably more efficient than everyone else’s, given how well it had been doing its job while being starved of space.

The problem with a myxoma is not simply that it takes up space. If it gets large enough, it can obstruct blood flow through the atrial valve. Also, they are “friable,” meaning bits can break off, enter the bloodstream, and go places where bits of heart tumour really ought not go.

In retrospect, it also provided an explanation for health problems I had been experiencing that nobody had previously connected to my heart. My doctor had not been looking for a myxoma. There was no particular reason he should have been, given their rarity.

One week after it was discovered, I was in Strathfield Private Hospital having open-heart surgery to remove it.

Everybody has an open heart

I had never had major surgery before. I also don’t think I have taken a real sick day in my academic career. I have taught through pneumonia and through laryngitis, although I ended a class early that day.7

Open-heart surgery is another matter though.

Among the instructions on leaving hospital was that I would not be able to drive a car for several weeks. Ha. I also did not, however, ride a bicycle to or from the hospital.

My myxoma

The tumour was successfully removed from my left atrium. It was as expected a myxoma and benign, but after extraction measured at roughly 70 mm, confirming that removing it was the right strategy. The surgery involved stopping my heart and lungs, so I was kept alive by machines in the interim. I of course only know this because I was told, having been unconscious through the experience. Technically they opened me up twice, since there was still internal bleeding after they closed me the first time. Lovely.

Recovery from having one’s chest opened is not instantaneous. The first week in hospital was miserable, both because of the surgery and the tubes and because of being in hospital with all the machines that go ping. Walking, breathing, sleeping, coughing, and figuring out how to get out of a chair became more challenging than I remembered.

But the operation went well, the myxoma is gone, I have spent a month recovering (and will spend at least another two months they tell me, but I am fine to do anything not involving heavy lifting) and I am back at on campus facing a month of computer software needing updates which for whatever reason they need to waste my time for instead of doing when I wasn’t here for a month, with the computer on.

Causal Chain

The chain of causation here.

• My cholesterol was moderately high.

• My GP worried about it.

• I couldn’t tolerate the obvious treatment.

• That led to further investigation.

• The investigation showed that the cholesterol was not, in fact, doing very much damage.

• And in establishing that, the scan happened to find a large tumour in my heart before it could cause a stroke, obstruct blood flow, or do something else unpleasant.

• So my borderline high cholesterol may have saved my life.

My thanks to my GP for following up something that would have been easy to dismiss, and to the cardiologists, surgeons, nurses, physiotherapists, and other staff who diagnosed the problem, got me through surgery, and put me back together at Strathfield Private Hospital, and the cardio-physio group at St. George’s Hospital. Also thanks to the health care system in Australia, I am out-of-pocket well less than $AU10k for the whole thing. Also thanks to family and colleagues for picking up the slack.

3

I describe the CT scan as the worst amusement park ride ever. You lie on your back and they move you backwards and forwards while scanning you. Not painful (and not as claustrophobic as an MRI).

Read more

• Levinson, D. (2026) Testing Pedestrian Flow and Delay Estimation from First-Actuation Latency. Findings, August 20, 2026. [doi]

Traffic signal controllers timestamp the first pedestrian actuation that requests service, but they do not count the people arriving before the Walk indication. We test a theory-based estimator that treats the time from flashing-don’t-walk onset to first actuation as a censored waiting-time observation from a Poisson arrival-event process. The inferred event count and delay are calibrated separately to observed pedestrian counts and observed delay. Fourteen manually observed cases give mean adjustments of 2.202 for counts and 2.176 for delay assuming 100% compliance. A separate 24-leg-session video dataset gives 2.203 and 2.233. Held-out count errors are 23.9% and 22.4%. Observed behavior reduces delay from 16.606 to 15.996 pedestrian-hours in the manual data and from 12.934 to 8.522 hours in video.

Keywords:

pedestrian counts, pedestrian actuation, Poisson arrivals, signal delay, noncompliance, traffic signals, SCATS, Sydney

Writing and editing are, ideally, two stages in a complete creative process, yet we often prioritise the act of creation over the art of curation. The process of writing is mostly additive, with authors, starting with a blank page, spending the majority of their time on adding content rather than subtracting. This imbalance leads to verbose texts that obscure the core message, wasting the reader’s time.1.

Drawing from the metaphor of Michelangelo’s David, where the sculptor’s task was to reveal the figure already in the marble, “geological processes” of creation are akin to the writer, while the editor, our Michelangelo, must refine and shape the existing material. Sadly, Geology gets no credit despite having created the marble, and thus David.2 Yet, this editorial role is often undervalued, despite clarifying and distilling ideas for the reader, saving the reader time, lowering their costs of idea acquisition, and increasing their net value.

In the era of large language models (LLMs), which are inherently additive in nature, balancing creation with creative destruction is required to offset tools that flood the market with content quickly. LLMs are unmotivated to subtract,3 which is essential for clarity and impact. This shift from scarcity to abundance in content creation demands a renewed emphasis on curation.

FIN.

Read more

When there's an ad-wrapper on the bus you ride, 
so you can’t clearly see outside, that’s enshittification.

When someone leaves a shared e-bike 
on the footpath you hike, that’s enshittification.

When a billboard appears
right where you walked freely for years, that’s enshittification.

When the cycle runs so long 
the walkers stand till dawn, that’s enshittification.

When a car’s tuned to roar 
so the whole block can hear even more, that’s enshittification.

The 2024 word of the year, coined by Cory Doctorow,1 does not just describe internet platforms, it describes a lot of the erosion and destruction of the commons we face in urban environments, destruction at the hands of international corporations, local governments without much sense, state traffic engineers maximising vehicle throughput, or just your local neighbourhood assholes.

This is why we have to have rules and regulations and laws backed by police with guns, because too many people are selfish jerks without either any concept that what they are doing is a problem, or not caring.

Council officials who fail to do anything are complicit in the enshittification of the pedestrian realm.

All of which is to say: Operations (which deals with today’s people moving on today’s network) is more important than Planning (which deals with a small increment of additional imaginary future people moving on imaginary future networks), and we spend relatively little effort on it.

FIN

Read more

Welcome to the latest issue of The Transportist, especially to our new readers. As always you can follow me on Mastodon, BlueSky, or RSS.

You might have noticed the site logo changed. Been meaning to for a while, but prompted when I received a nasty-gram from Transport for London, who worried, I suppose, you (well not you, but someone) might be confused that this here newsletter was a transit stop and not a newsletter, so they must protect their trademark, despite the roundel being a universal symbol, me being in Australia, and the newsletter being hosted in the US. Roundels are an old visual form. They appear in heraldry, flags, aviation, military insignia, civic marks, and commercial design. The form long predates London Transport, and is widely used outside London. Feel free to send in pictures of people abusing the roundel for non-authorised purposes, and I will share them over time to help out the lawyers at TfL (or inundate them with too many signs to chase down).

Pointers

Transit & Cities

• The Transit Abundance Playbook — Institute for Progress

• How Madrid Built the World’s Best Metro — YouTube

Automation

• China Resumes Issuing Robotaxi Licenses After Months-Long Freeze — Bloomberg

• We took a self-driving car on the road for 100 days to see how it handled itself – these are the mistakes it kept making — Zuduo Zheng, UQ News / The Conversation

• San Francisco’s fireworks show ends in hours of gridlock involving Waymo cars — NBC Bay Area

Roads & Behaviour

• Supercars, viral clout and the Sydney suburbs left sleepless — Sydney Morning Herald (hooning)

• This Simple White Line Is America’s Greatest Unsung Innovation — Ben Cohen, WSJ

• Former Italian motorway boss among 32 convicted over Genoa bridge tragedy - Reuters

Policy

• Californians sour on Newsom’s push to ban gas-powered cars— George Skelton, Los Angeles Times (Newsom and EVs)

• Digital travel declaration to replace paper incoming passenger card — The Guardian

Elsewhere

• There’s a Global Network of Fungi Under Your Feet. This Is the First Complete Map — Wired

Supply Chains

• The U.S. is using an Iranian smuggling tactic to sneak oil out of the Gulf -

Animal Transport

• Central Park Horse Carriage Death ends industry

Your regular reminder that cars are weapons

• Militant attack on Pakistan Rangers HQ in Karachi sparks gunfire

• Attack on Berlin Pride Parade

Posts

Publications

Press

Charis Chang on SBS posted High-speed rail is a decades-old Australian dream. One factor could finally make it real 28 June 2026

The Quote

But professor David Levinson, civil engineer and transportation analyst at the University of Sydney, is sceptical about the project and says, if delivered, it would likely feature the longest high-speed tunnel in the world.

“As shown by Snowy II and the M6 Motorway in Arncliffe, things can go wrong with tunnelling, driving up costs,” he tells SBS News.

In engineering we talk about quality, speed, and cost — and generally you can only get two out of three.

“They are proposing to open this in ten years, and make mention of using new ‘green’ concrete technology, which obviously brings with it risks, as does any new technology.”

The Full set of questions I answered:

1. Despite many proposals for high-speed rail in Australia, none have got off the ground, why is this?

They have always been considered too expensive for the benefit provided. Even if they are worthwhile for society, finding the financing for them has always been difficult. One imagines some kind of public-private partnership, like some Australia states do with TransUrban, where there is a contract paying the provider revenue and an availability payment in exchange for the up front investment (usually from superannuation funds) over a fixed term. Whether this maximises benefits for Australia is unclear. And it is unclear why everyone in Australia should pay for a line in a single corridor serving Newcastle and Central Coast, while other corridors remain underserved.

2. Do you think the current proposal is any different from previous ones?

The released documents show a Benefit/Cost ratio under 1.0 under all but the most optimistic assumptions. This proposal has also made more optimistic assumptions about land use changes and “Wider Economic Benefits” about which Treasury officials are generally skeptical.

I refer you to page 9 of the IA Business Case Evaluation Report

Also see the Business Case (section 7.6)

It is different from previous proposals in that it serves even fewer people.

3. The Newcastle and Sydney section is considered the most challenging to deliver – why is this? What are the engineering challenges?

As proposed by the Commonwealth it includes an extensive amount of tunnelling, probably the longest high-speed rail tunnel in the world. As shown by Snowy II and the M6 Motorway in Arncliffe, things can go wrong with tunneling, driving up costs. In engineering we talk about Quality, Speed, and Cost, and generally you can only get two out of three, Prioritising Speed and Cost will lost Quality, prioritising Cost and Quality will lose Speed, etc. They are proposing to open this in 10 years, and make mention of using new “green” concrete technology, which obviously brings with it risks as does any new technology.

4. I’ve been told that keeping the travel time to 1 hour would be ideal so that Newcastle can be within reasonable commuting time to Sydney, is this feasible?

If they build it, 1 hour point-to-point (i.e. station-to-station) is feasible. Whether this is “a reasonable commuting time to Sydney” is an open question. Note it assumes the commuter lives on top of the station at Newcastle, and works on top of the station at Central. I can take 10 minutes just to get from a train to the exits at Central Station, so access and egress costs need to be considered. If someone is transferring trains or to buses at Central, that is also added time to the final destination. Most people in Sydney don’t actually work at Central station, which is the southern end of the CBD.

But all of this assumes cities will retain their same importance if the future that they have today, despite Work-from-Home, AI, and all of the technological changes we cannot foresee.

It also assumes a “Big Australia” that growth via migration will keep coming. I don’t believe the party currently polling number one agrees with that forecast. In the absence of migration, Australia would be losing population.

5. Do you think this project will actually happen?

“Rationality” is not the word most associated with government.

I also asked a local LLM (Ollama) which has access to my corpus. It answered as below:

• High-speed rail projects in Australia face challenges due to fiscal risks from cost overruns and uncertain operating-cost recovery, which create unacceptable risks for states

• The Newcastle and Sydney section is particularly challenging due to complex geography, existing infrastructure, and the need for high-speed corridors that balance speed with safety and environmental constraints

• Keeping travel time to 1 hour between Newcastle and Sydney is feasible in theory, but it requires significant investment in infrastructure and operational efficiency to meet such a tight timeframe

• The current proposal is not fundamentally different from previous ones, as it still faces similar fiscal, technical, and political hurdles that have historically stalled high-speed rail in Australia

• The project’s success depends on overcoming these challenges, but without substantial funding and political will, it may not materialize as planned

Random Videos

• Nice use of transport examples to explain hash tables, featuring the work of Andrew Krapivin. The video probably has an AI voice, but the explainer is good.

• conduct high-quality research in quantum-enabled computational approaches for digital twins and complex system simulations

• develop, implement, test, and benchmark computational models, algorithms, data pipelines, and research software prototypes

• contribute to optimisation, simulation, sampling, or uncertainty-modelling approaches for complex systems

• analyse infrastructure, spatial, temporal, networked, or urban systems data
  contribute to the preparation and submission of journal articles, conference papers, technical reports, and research outputs

• collaborate with interdisciplinary scholars across engineering, design, planning, computing, and related research domains

• contribute to stakeholder engagement activities, including workshops, research presentations, and partner-facing materials

• assist with the development of competitive grant applications and future external funding opportunities.

Work Rights
You must have unrestricted work rights in Australia for the duration of this employment to apply. Visa sponsorship is not available for this appointment.

Link: https://usyd.wd105.myworkdayjobs.com/en-GB/USYD_EXTERNAL_CAREER_SITE/job/Darlington-Campus/Postdoctoral-Research-Associate-in-Applied-Quantum-Computing-Research_0153792-2

• Song, C., Levinson, D. and Moylan, E. (2026) A simulation-based policy evaluation of healthcare access using heterogeneous emergency medical services vehicles and incidents. Transport Policy, Volume 187, October 2026, 104293. [doi]

Efficient dispatch policies are critical for ensuring equitable and effective emergency medical services (EMS). While vehicle specialisation offers tangible clinical benefits, integrating vehicle types into dispatch policy presents significant challenges. This study employs an agent-based simulation framework to evaluate the effects of alternative dispatch policies under varying proportions of specialised ambulances. Results indicate that allowing specialised vehicles to respond to a broader range of high-priority incidents enhances overall survival rates. However, the benefits of specialisation depend on how these vehicles are deployed within the system. When the supply of specialised vehicles exceeds demand, restrictive policies lead to longer response times and worsened outcomes for non-prioritised cases. In particular, restricting specialised vehicles to a narrow set of incidents can reduce overall system efficiency by limiting dispatch flexibility and increasing waiting times for other patients. Moderately flexible dispatch policies provide balance between outcome efficiency and response equity. These findings suggest that both the proportion of specialised vehicles and their dispatch eligibility should reflect the underlying mix of incidents in order to avoid over-constraining the system. Spatial analysis shows that survival and response disparities are more pronounced in peripheral areas. These findings underscore the need to align dispatch policy and fleet composition with incident typology and spatial demand, offering actionable insights for EMS policy and resource planning.

Keywords:

Dispatching policy, Emergency medical services, Agent-based simulation, Vehicle classes, Incident types, Priority

• Gao, Y. and Levinson, D. (2026) A stochastic queueing model for travel time reliability with spatial density heterogeneity. Transportation Research Part B, Volume 211, September 2026, 103544. [doi]

This paper constructs a theoretical model connecting day-to-day travel time reliability (TTR) and vehicle density, testing it on freeway stretches in Minneapolis - St. Paul and San Diego. We establish the presence of a counter-clockwise hysteresis loop between average vehicle density and experienced travel time standard deviation. We also observe that vehicle density heterogeneity exerts a more profound effect on TTR during moderate congestion. We find that a timehomogeneous Poisson process accurately characterizes the vehicle arrival process on segments of freeway stretches, both with and without on-ramps, during the morning peak period. The travel times for these segments align well with an exponential distribution. Through an analysis of the travel time correlations among different segments of the freeway stretch, we find that this correlation is higher during congestion offset periods, resulting in more severe travel time fluctuations due to increased density heterogeneity. Using the M/M/1 queueing model, we derive a model encapsulating the variance of experienced travel time, average vehicle density, and density heterogeneity for freeway stretches consisting of multiple segments. We use the `birth-death process’ to model the relationship between average vehicle density and density heterogeneity. By integrating these two models, we derive a novel model that accurately approximates freeway stretch TTR based on average vehicle density and traffic flow. We apply our models to TTR changes on the two selected freeway stretches to validate across different time periods and select two subnetworks, each containing three additional freeway stretches, to validate across spatial dimensions. The results from these experiments corroborate the robustness and generality of our model across both temporal and spatial contexts.

Keywords:

Travel time reliability, Density heterogeneity, Queueing theory

• Levinson, D. (2026) Braess’s Paradox Implies Reduced Demand. Findings, June 30, 2026. [doi]

Induced demand is usually interpreted as additional capacity reducing generalized cost and producing more travel. When a network exhibits Braess’s paradox, an added link raises user-equilibrium cost, and we would thus expect demand to fall. I show this in Braess’s original four-node numerical network with linear link costs and inverse demand. In the default case, the added link raises elastic equilibrium cost from 70.14 to 80.00 and reduces demand from 3.66 to 3.33. The reported 143-point sweep maps the Braess region in inverse-demand space; no sign-inconsistent cells appear. The accompanying browser implementation reproduces the reported comparison and sweep.

See also:

BRAESS– Braess Paradox Explorer

BRAESS demonstrates fixed-demand and elastic-demand user equilibrium on a small editable network.
More >

• Soltani, A, Ramezani, M. and Levinson, D.M. (2026) A stochastic delay model for signal-free intersections. Transportation Research part C. October 2026, 105813, Volume 191. [doi]

Highlights

• Stochastic conflict-probability model estimates delay at signal-free intersections without fixed priority hierarchies assumption.

• Binary service time distribution links conflict probability to M/M/1 and M/G/1 queueing delay formulations.

• Validated using real data across intersections, roundabouts, and merging sections with significant improvement over HCM.

• Extended to autonomous vehicle coordination under FCFS and CfDCA protocols.

• Dynamic parameter evolution accommodates time-varying demand through quasi-steady-state regime switching.

Abstract

This study presents a stochastic delay model that treats signal-free intersections as systems of servers where the probability of conflict between vehicles determines delay. Rather than relying on predetermined major-minor hierarchies, the model builds on interaction between any two approaching vehicles attempting to occupy the same conflict zone simultaneously. This conflict-probability framework applies across many traffic scenarios, from traditional unsignalized multi-modal intersections, merging sections, and roundabouts to signal-free intersections for autonomous vehicles (AVs). The model employs queuing theory formulations where service time depends on conflict probability and clearance time for conflict zones. The model extends to multi-movement intersections through dependent and independent conflict zone networks and accommodates time-varying demand through dynamic parameter adaptation. Theoretical analysis reveals that equal inflows maximize delays due to peak conflict probabilities. Validation using real-world trajectory datasets demonstrates improvements over Highway Capacity Manual and Austroads methods across diverse scenarios. Furthermore, the proposed delay model achieves mean absolute errors of 4.6 to 10.9 s using simulation of signal-free intersections for AVs under first-come first-served and communication-free distributed control algorithm protocols.

Keywords

Signal-free junction; Stochastic modeling; Probability of conflict; Autonomous vehicles; Conflict networks; Queue theory

1. Authors should use paid AI (see 2) before submitting. They should use it not just to clean up English but as a hostile referee. Ask your LLM of choice (mine at this stage of history is ChatGPT and Codex) what is wrong with the paper. Ask it to review the paper like a peer reviewers for the journal you are planning to submit to, ask what is unclear, undefined, multiply-defined, unsupported, unreplicable, under-cited, overclaimed, or likely to irritate Reviewer 2. Once you satisfy your LLM of choice with revisions, use a second LLM and repeat, it will find different things. Of course ask it how it would revise the paper as well, but don’t just accept it at face value. This does not guarantee acceptance, but not doing this will probably soon guarantee rejection. As discussed below, reviewers and editors are likely to be using AI too, and perhaps better (more tokens, more advanced, more expensive) AI than the authors used. Even then, reviewers will find something “wrong”, because that is how reviewers are. They are not paid. Their reward is anonymous criticism. (For-profit journals should pay reviewers.)

2. Newer paid AI is much better than a year ago. This is not just a smoother autocomplete. Free AI and paid AI are different tools now. Paid AI can read the paper, follow the method, look at the code, question the equations, find unsupported claims, and write something that looks a lot like a referee report. For technical work, the Codex (or Claude Code) version is better than the ChatBot version, because transport research is dominated by code, data, equations, maps, tables, and claims about the world. Make the investment in yourself.

3. Reviews are already being done with the help of AI, or entirely by AI. This is happening whether or not journal policies have caught up. This is done by some editors as well, I believe but cannot prove, who are having trouble finding reviewers.

4. Editors should use AI as a screener before sending papers to human review, especially at the desk-reject stage. This should be fully disclosed to authors. This would be a first pass: Is the paper in scope? Is there a research question? Do the claims follow from the evidence? Is the method described? Are the data and code available? Is the literature review just a pile of citations? Is this paper wasting everyone’s time? This would help editors. It would help authors. It would save scarce human reviewer time.

5. AI should be used after human review too. Did the authors actually answer the referee reports, or just write “we thank the reviewer for their insightful comments” 37 times? Are the data and code available? Do the tables support the claims? Are they internally consistent? Are the variables in the equations defined properly, do variable definitions slip across the paper? Are the citations real? Are the limitations stated? These are basic scientific checks. Humans need not do all of this by hand.

6. AI is now, in June 2026, good enough to mostly write, under supervision, an acceptable paper in many transport journals, if there is a good research question, available data, a real method, and a human who knows what they are doing. It can also draft a theory paper. This is no longer hypothetical. It can write, iterate, and revise.

7. AI still does not yet generally generate good questions. That remains, so far, the human job. The scarce skill is knowing what is worth asking, what evidence matters, what claims are justified, and why anyone should care.

FIN

Read more

• Levinson, D. (2026) The ‘b’s’ Knees: Logistic Stage-Transition Rules as Percentile Conventions on a Standardised Time Scale. Findings, June 1, 2026. [doi] [Data/code]

Logistic diffusion is often described as passing through early growth, rapid growth, and maturity, but the dates separating these stages, the knees of the curve, are defined in different ways across fields. This note brings several familiar stage-transition rules for the standard logistic curve into one common form. Each symmetric analytic rule can be written as t0 +/- c/b, where b is the logistic growth-rate parameter and t0 is the inflection date. Equivalently, each rule implies a fixed percentile window of the asymptote K. The paper shows that common stage-transition conventions differ by the implied percentile window, and provides a synthetic Python example comparing analytic rules with a free segmented-regression benchmark.

Keywords: logistic growth, diffusion of innovations, stage transitions, sigmoid curves, technology diffusion, inflection point, percentile conventions, segmented regression

I have also uploaded a lot of our shareable code and data to Github recently, you might follow that.

I will be at WSTLUR 2026 in Beijing this June, and then visit Chengdu and Hangzhou, maybe I will see you there.

Pointers

Transit

• London and New York public transport use seems to have settled at 70–80% of the pre-pandemic peak, reflecting (mostly) WFH. Fridays are down 40%. [LONDON] [NYC] (h/t Ben Evans, Benedict’s Newsletter)

• Sydney’s first electric ferry two years off as ambitions for entire fleet sink

• Egypt opens high-speed monorail linking Cairo to desert capital

Transit Data

• Real-time map of TfL

• Mapping the Speed of Surface Transit

• Timetable World — an archive of historical timetables, with a research section worth poking around in.

Parking

• Beaches should be free: row erupts over Sydney council’s paid parking plan

Security

• Iranian hackers responsible for Los Angeles transit system breach, Israeli researchers say

• US Education provider (KKR-owned) Instructure (d/b/a Canvas) was hacked, bringing the system down globally. ShinyHunters were paid. I really liked Moodle. I feel there has been no substantive progress in Canvas in nearly a decade, so they are just engaged in extraction, and that Universities (and High Schools!) keeping their student data remotely is just begging for trouble.

Infrastructure

• Albanese government slashes funding for Inland Rail project — but HSR continues

Aviation

• Frontier Air flight may have struck person on Denver runway

• Spirit Airlines went under. My review from 2015 must have done it.

• Vivid Sydney Drone Incident (Drones fall from the sky)

Bottlenecks

• Strait of Hormuz payment system in the works (Spatial monopolies be spatial monopolising)

• Austrian protesters shut vital motorway connecting Germany to Italy

Ridesharing

• Lyft gets Gett UK

• Ridesharing Institute Conversation, 22 April — Paul Minett’s lightly-edited recording of a conversation on fuel-crisis responses in Norway, the UK, Germany, and Australia, and on pooling as a demand-side policy lever. I might have said some things.

Reality television and its deleterious consequences for civilisation

• Following the Money on Sean Duffy’s [US DOT Secretary] Road Trip

Speed

• Hazelwood road signs vandalised over reduced speed limits, Victoria

• The Embedded Defaults of Cars [A nice blogpost from a UCLA student]

AI

• Could AI’s leading men become as powerful as Ford or Rockefeller? — The Economist.

• It would be highly ironic if stories about evil AI, warning of the risks of AI, were the parts of the training set that caused AI to act evil. And yet here we are.

Your regular reminder

• Two killed, multiple injuries after car hits bystanders in Leipzig

• Eight injured, four critically, as car rams into pedestrians in Italian city

• Cornell University president accused of backing car into protesters following Israel/Palestine debate

Posts

Publications

Press

• Australia’s $90 billion high-speed rail plan faces major hurdles — 7News. I was quoted.

But the challenging terrain means at least 70km of tunnels, making it the most tunnelled high-speed rail line in the world.

“We have more experience with tunnelling, and tunnel boring machines have gotten better. But this is a significant leap,” said Professor David Levinson from the University of Sydney’s School of Civil Engineering.

Professor Levinson warned the cost per kilometre is higher than any other high-speed rail in the world, including California’s troubled project.

• Previous road closure traffic study suggests commuters more flexible than expected - WAVE. I was interviewed

LOUISVILLE, Ky. (WAVE) - For the upcoming I-65 summer shutdown, KYTC says plan to add 15 minutes during rush hour. But the question hanging on commuters minds, just how bad will traffic be?

Traffic engineers have been able to study major closures to learn about the impact on traffic flow. A professor who wrote a reporton what happened after the I-35W bridge collapse in Minneapolis in 2007 said traffic patterns here may not be as dire as expected.

The I-35W bridge carried 140,000 cars a day. But after it collapsed in August 2007, researchers didn’t find those cars choking up traffic on every other road. They only saw 90,000 cars from that interstate.

“50,000 vehicles disappeared. They no longer crossed the Mississippi River. Now, that doesn’t mean that the people didn’t make trips, but they made trips to different destinations,” said David Levinson, a University of Sydney Professor of Transport.

Levinson said their research after the Minneapolis bridge collapse learned drivers are more flexible than previously thought. “Carmageddon” in Minneapolis didn’t actually occur.

“And things would, of course, be more congested if everyone had traveled the same way, but everyone expected everyone else to travel the same way. So they decided not to travel that day if they could avoid it,” Levinson said.

No one planned for I-35W to collapse. Levinson’s study says there is a difference for construction closures like the I-65 summer shutdown, but not how you might think. Drivers adjust pretty well when they’ve had time to plan.

“I mean, there’s no question that there’ll be more traffic on the parallel roads. But I don’t think it’ll be the worst case scenario. I think people will have some flexibility about when they travel,” Levinson said.

He points out schools are out and people go on vacation. Unlike 20 years ago, GPS is also commonplace. More people may be willing to try a totally new route in place of I-65.

“People are more willing to go places because they know that they will not get lost. And I think fear of getting lost was a huge deterrent to a lot of travel before we had Google Maps and other types of live information,” Levinson said.

Levinson’s study found the traffic network was able to find balance around a planned closure. It took six weeks for traffic to find balance after the I-35W bridge collapse.

Monday’s commute may be influenced by how many people pay attention to the signs, the stories and the warnings about the I-65 summer shutdown.

• Hao, W., Fang, Y., and Levinson, D. (2026) User-organized pre-pooled ride-hailing: exploring a new mode. Transportation Research Part D: Transport and Environment Volume 157, August 2026, 105422 [doi]

User-organized Pre-pooled Ride-hailing (UPR) is a user-coordinated form of shared mobility that layers social media coordination on top of commercial ride-hailing within bounded trust-based communities (e.g., campuses, workplaces, or residential compounds). We designed a comprehensive survey with 24 choice scenarios and integrated sociodemographic, revealed behavior, and attitudinal measures including environmental perceptions, then estimated mixed logit models for all respondents and for organizers versus followers. UPR is most competitive for longer, daytime trips and for first-/last-mile access to metro hubs, offering a lower per-person cost than solo ride-hailing and faster door-to-door travel than public transport. UPR choice is negatively associated with ride-hailing and platform ride-pooling use, implying substitution. Climate-mitigation beliefs increase UPR choice probabilities, while stronger trust requirements and privacy concerns constrain uptake. The findings highlight how environmental perceptions and community trust jointly shape decentralized pooling and its potential role as a low-impact complement to transit in fringe areas.

Keywords:

User-organized pre-pooled ride-hailing (UPR), Competition and cooperation, Travel behavior, Shared mobility, New mobility, Ride-hailing, Carpooling

• MILLS, S., LEVINSON, D. (2026) Missed Opportunities: Using Access to Assess Alternative Historical Urban Rail Networks. Case Studies on Transport Policy [doi]

In this paper, we use Sydney as a case study to reassess past and proposed rail lines through an accessibility-based appraisal framework. We estimate changes in job accessibility under alternative network configurations and monetise those changes using land-value uplift implied by previously estimated Sydney hedonic models. We treat this land-value uplift measure as a partial indicator of capitalised accessibility benefits, rather than a full substitute for conventional cost-benefit analysis. We review Bradfield’s 1916 heavy-rail proposal, the 1974 Sydney Area Transportation Study (SATS), the 2001 Long Term Strategy for Rail, and Sydney Metro 2056 proposals, and we also examine two revised heavy-rail or metro routes and several light-rail options. Costs are benchmarked from recent Sydney and international projects, and benefit/cost ratios are reported under multiple discount rates. The results identify several historical and revised alignments that perform well under this access-based land-value metric, while also showing the importance of cost assumptions and the interpretation of land-value uplift in policy appraisal.