I’m sorry to hear about the death of Mark Stephens, as reported on Reddit. He wasn’t the first or last InfoWorld columnist to write under the name “Robert X. Cringely,” but he was the Cringely who was a tech-media phenomenon in the 1980s and 1990s. https://news.ycombinator.com/item?id=49949438

A five-year-old girl is fighting for her life, and five other people are being treated in hospital for injuries, after a car ploughed into a crowd of Knights supporters in Newcastle on Saturday morning.

Personal safety often gets more attention than road safety. Both are important, but I would guess people misunderestimate their relative magnitude. I looked at some data from New South Wales, which to be clear is significantly safer on both dimensions than the US. In recent years, New South Wales has recorded the following statistics: Homicides: There were 85 murders in 2024, the highest annual count since 2014. In the 12 months leading up to March 2026, there were 87 recorded murder victims. (See: On Bondi Beach) Road Deaths: * Road Fatalities: In 2025, 355 people died on NSW roads, vs 327 in 2024. Speeding was associated with 134 deaths in 2025. * Pedestrians: 54 deaths, representing a 25.6% increase from the previous year. The majority of the 54 pedestrian deaths occurred on everyday suburban streets. Older road users (aged 70+) were particularly affected, accounting for 18 of these pedestrian fatalities. * Cyclists: 15 deaths (including three e-bike riders), which was a 200% increase over the 5 fatalities recorded in 2024. Cycling has notably increased with the advent of e-bikes in recent years. These increases occurred despite (because of?) broader national efforts to improve safety for vulnerable road users. The state government simultaneously blames drivers for driving too fast while opposing safe speed policies, and opposing the use of regulatory devices like unmarked speed cameras. --- FIN Read more

Personal safety often gets more attention than road safety. Both are important, but I would guess people misunderestimate their relative magnitude. I looked at some data from New South Wales, which to be clear is significantly safer on both dimensions than the US. In recent years, New South Wales has recorded the following statistics: Homicides: There were 85 murders in 2024, the highest annual count since 2014. In the 12 months leading up to March 2026, there were 87 recorded murder victims. (See: On Bondi Beach) Road Deaths: * Road Fatalities: In 2025, 355 people died on NSW roads, vs 327 in 2024. Speeding was associated with 134 deaths in 2025. * Pedestrians: 54 deaths, representing a 25.6% increase from the previous year. The majority of the 54 pedestrian deaths occurred on everyday suburban streets. Older road users (aged 70+) were particularly affected, accounting for 18 of these pedestrian fatalities. * Cyclists: 15 deaths (including three e-bike riders), which was a 200% increase over the 5 fatalities recorded in 2024. Cycling has notably increased with the advent of e-bikes in recent years. These increases occurred despite (because of?) broader national efforts to improve safety for vulnerable road users. The state government simultaneously blames drivers for driving too fast while opposing safe speed policies, and opposing the use of regulatory devices like unmarked speed cameras. --- FIN Read more

#LimeBike Sculpture, #Sydney

Chapter 11 (pp. 84–91) from The Reconstruction Papers.

Below summarises my presentation at a Forum on Vehicle-Generated Noise Pollution at New South Wales Parliament House on September 23. For my international readers, while noise is an issue in many places, in Australia this is an issue because of the popularity of hooning, anti-social operation of vehicles, especially noisy driving (modified engines, tyre burnouts (spinning the driven wheels while holding the car still), etc.) Wikipedia reports: A hoon (/huːn/ ⓘ) is an Australian and New Zealand term describing a person who deliberately drives a vehicle in a reckless or dangerous manner, generally in order to provoke a reaction from onlookers. Decibels If a tree falls in the forest and there is no-one there to hear it, does it make a sound? Of course. But does it make a noise? No. Noise is unwanted sound. It is a negative externality; it requires both someone making the noise and someone hearing it without wanting to. What matters to the person trying to sleep is how loud each event is and how many events there are. In contrast with intuition, decibels are logarithmic. One truck may be 80 dB, but two trucks are “only” 83 dB. Ten decibels more sounds about twice as loud, so a modified motorcycle at 90 dBA is heard as sixteen times louder than a 50 dBA street. A quiet street with one loud vehicle is worse than a busy one with a steady stream of vehicles. The background is low and every pass stands out. Money We have heard from my colleague Edmund Lau at the University of Sydney about the health effects of poor sleep, resulting from noise. But everything in Australia is about real estate. Hedonic studies of real estate prices near highways and airports give us a Noise Depreciation Index. Each additional decibel lowers the price of a house by about 0.62%. People don’t want to live near highways or under flight paths, and require a lower price to do so. Roads that invite it Some roads invite anti-social driving: long straight sections with clear sightlines, capacity to spare at night, connected loops that let a driver circulate and repeat the performance. Hard reflective surfaces, façades close to the carriageway, and light background traffic amplify the noise. Re-design Design works every hour on every driver. Geometry that enforces itself changes what speed feels natural, and it narrows the whole speed distribution, including the fast tail that does the damage. Design changes may comprise various sorts of traffic calming (but not all of them), including interventions like planting trees on the side of the road, to slow traffic. Isolated humps and stop signs produce the noisiest pattern available. Brake, sprint to the next device, brake again. The braking, the suspension and the re-acceleration all make noise. Continuous low-speed geometry is quieter: close-spaced plateaus, raised intersections, and small roundabouts, along with traffic signals timed to give a green wave at the target speed rather than a clear run. Diverters cut flows and speeds together. Lower speeds also lower the level. Zurich dropped limits from 50 to 30 km/h and measured about 1.6 to 1.7 dB less at building façades, with less annoyance and less disturbed sleep reported. Re-surface Transport for NSW notes that against dense-graded asphalt: new open-graded asphalt −2 dBA, stone mastic asphalt −1, 7 mm chip seal +2, 14 mm chip seal +4. Road pavement gets resurfaced on a cycle, we might as well put down quieter pavements when we can. Enforce Enforcement is our go-to policy, and we cannot abandon it. It is necessary for modified exhausts, organised racing and repeat offenders, and cameras and patrols can follow the problem as it moves. But we must also recognise it is selective by nature. And it addresses the problem that previous bad designs have created, and hopefully future good designs will prevent. What Parliament can do Three things, none of which requires another study. * Redesign. Self-enforcing 30 km/h design at noise hotspots, and on new residential, school and shopping streets. Fund calming along whole corridors, not single blocks. * Resurface. Fund low-noise surfaces, and specify them where people live. * Enforce. Objective noise limits that can be measured at the roadside, backed by cameras, patrols and inspections aimed at modified exhausts, organised racing and repeat offenders. All of which is to say: enforcement catches the offender, design removes the opportunity. FIN --- Notes Electric vehicles Electric propulsion is quieter, and below about 30 km/h that is most of the sound. Above it, tyre-road noise dominates and an electric car sounds like any other. Read more

Orlando-to-Miami route seeking to popularise high-speed rail in US has filed for Chapter 11 to cut nearly $6bn in debt

Below summarises my presentation at a Forum on Vehicle-Generated Noise Pollution at New South Wales Parliament House on September 23. For my international readers, while noise is an issue in many places, in Australia this is an issue because of the popularity of hooning, anti-social operation of vehicles, especially noisy driving (modified engines, tyre burnouts (spinning the driven wheels while holding the car still), etc.) Wikipedia reports: A hoon (/huːn/ ⓘ) is an Australian and New Zealand term describing a person who deliberately drives a vehicle in a reckless or dangerous manner, generally in order to provoke a reaction from onlookers. Decibels If a tree falls in the forest and there is no-one there to hear it, does it make a sound? Of course. But does it make a noise? No. Noise is unwanted sound. It is a negative externality; it requires both someone making the noise and someone hearing it without wanting to. What matters to the person trying to sleep is how loud each event is and how many events there are. In contrast with intuition, decibels are logarithmic. One truck may be 80 dB, but two trucks are “only” 83 dB. Ten decibels more sounds about twice as loud, so a modified motorcycle at 90 dBA is heard as sixteen times louder than a 50 dBA street. A quiet street with one loud vehicle is worse than a busy one with a steady stream of vehicles. The background is low and every pass stands out. Money We have heard from my colleague Edmund Lau at the University of Sydney about the health effects of poor sleep, resulting from noise. But everything in Australia is about real estate. Hedonic studies of real estate prices near highways and airports give us a Noise Depreciation Index. Each additional decibel lowers the price of a house by about 0.62%. People don’t want to live near highways or under flight paths, and require a lower price to do so. Roads that invite it Some roads invite anti-social driving: long straight sections with clear sightlines, capacity to spare at night, connected loops that let a driver circulate and repeat the performance. Hard reflective surfaces, façades close to the carriageway, and light background traffic amplify the noise. Re-design Design works every hour on every driver. Geometry that enforces itself changes what speed feels natural, and it narrows the whole speed distribution, including the fast tail that does the damage. Design changes may comprise various sorts of traffic calming (but not all of them), including interventions like planting trees on the side of the road, to slow traffic. Isolated humps and stop signs produce the noisiest pattern available. Brake, sprint to the next device, brake again. The braking, the suspension and the re-acceleration all make noise. Continuous low-speed geometry is quieter: close-spaced plateaus, raised intersections, and small roundabouts, along with traffic signals timed to give a green wave at the target speed rather than a clear run. Diverters cut flows and speeds together. Lower speeds also lower the level. Zurich dropped limits from 50 to 30 km/h and measured about 1.6 to 1.7 dB less at building façades, with less annoyance and less disturbed sleep reported. Re-surface Transport for NSW notes that against dense-graded asphalt: new open-graded asphalt −2 dBA, stone mastic asphalt −1, 7 mm chip seal +2, 14 mm chip seal +4. Road pavement gets resurfaced on a cycle, we might as well put down quieter pavements when we can. Enforce Enforcement is our go-to policy, and we cannot abandon it. It is necessary for modified exhausts, organised racing and repeat offenders, and cameras and patrols can follow the problem as it moves. But we must also recognise it is selective by nature. And it addresses the problem that previous bad designs have created, and hopefully future good designs will prevent. What Parliament can do Three things, none of which requires another study. * Redesign. Self-enforcing 30 km/h design at noise hotspots, and on new residential, school and shopping streets. Fund calming along whole corridors, not single blocks. * Resurface. Fund low-noise surfaces, and specify them where people live. * Enforce. Objective noise limits that can be measured at the roadside, backed by cameras, patrols and inspections aimed at modified exhausts, organised racing and repeat offenders. All of which is to say: enforcement catches the offender, design removes the opportunity. FIN --- Notes Electric vehicles Electric propulsion is quieter, and below about 30 km/h that is most of the sound. Above it, tyre-road noise dominates and an electric car sounds like any other. Read more

Hands free driving for the car you already have

There is a conflict at the heart of higher education: we are rewarded for teaching students and graduating them, but trusted to uphold standards that may require us to fail them. The institution selling the course also decides whether the customer has earned the certificate. 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?Wile E. Coyote will not fall until he realises he is no longer supported.1 Big rubric has been growing in size, I am unclear why it keeps getting fed. It is the appearance of fairness and efficiency I suppose, powered by the rubric-industrial complex (e.g. https://community.instructure.com/en/kb/articles/661102-how-do-i-add-a-rubric-to-an-assignment)2 In the US, Engineers (mostly Civil Engineers) sit the Fundamentals of Engineering exam around graduation and the Principles and Practice exam (and if passing become Professional Engineers) after about four years of work. NCEES writes and scores both. The university that taught the candidate does not. Neither exam is required to work as an engineer: the industrial exemption lets a company do its own in-house engineering unsealed. The licence is required to offer services to the public and to stamp drawings. The bar exam is required to practise law in almost every state. Wisconsin admits graduates of its two law schools without it, and Oregon, Washington, New Hampshire, Minnesota, and New Mexico have built supervised-practice or portfolio routes. Medicine examines most. USMLE Steps 1, 2, and 3 run from the second year of medical school into the first years of residency. After residency comes specialty board certification, a separate examination by one of the 24 ABMS member boards, and then continuing certification for the rest of a career. FIN Read more

A diminutive wild cat that inhabits Bolivia's cloud forest has been identified as a previously unknown species, marking the first time a new living cat species has been formally named and described ​in more than a century.

Congratulations to Dr. Amin Shaer for “satisfying the requirements for the award of the degree of Doctor of Philosophy at the University of Sydney.” 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 (

There is a conflict at the heart of higher education: we are rewarded for teaching students and graduating them, but trusted to uphold standards that may require us to fail them. The institution selling the course also decides whether the customer has earned the certificate. 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?Wile E. Coyote will not fall until he realises he is no longer supported.1 Big rubric has been growing in size, I am unclear why it keeps getting fed. It is the appearance of fairness and efficiency I suppose, powered by the rubric-industrial complex (e.g. https://community.instructure.com/en/kb/articles/661102-how-do-i-add-a-rubric-to-an-assignment)2 In the US, Engineers (mostly Civil Engineers) sit the Fundamentals of Engineering exam around graduation and the Principles and Practice exam (and if passing become Professional Engineers) after about four years of work. NCEES writes and scores both. The university that taught the candidate does not. Neither exam is required to work as an engineer: the industrial exemption lets a company do its own in-house engineering unsealed. The licence is required to offer services to the public and to stamp drawings. The bar exam is required to practise law in almost every state. Wisconsin admits graduates of its two law schools without it, and Oregon, Washington, New Hampshire, Minnesota, and New Mexico have built supervised-practice or portfolio routes. Medicine examines most. USMLE Steps 1, 2, and 3 run from the second year of medical school into the first years of residency. After residency comes specialty board certification, a separate examination by one of the 24 ABMS member boards, and then continuing certification for the rest of a career. FIN Read more

Congratulations to Dr. Amin Shaer for “satisfying the requirements for the award of the degree of Doctor of Philosophy at the University of Sydney.” 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 (

Recently published: * 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 economicsFig. 9. Spatial reorganisation of the urban economy under removal of the weekly fare cap. The maps display the percentage deviation from the base case for residential location, employment distribution, wages, residential and commercial floorspace prices, and total factor productivity.

Recently published: 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.

Recently published: 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.

Recently published: * 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 economicsFig. 9. Spatial reorganisation of the urban economy under removal of the weekly fare cap. The maps display the percentage deviation from the base case for residential location, employment distribution, wages, residential and commercial floorspace prices, and total factor productivity.

If you are reading this I survived open heart surgery to remove a Myxoma from my left atrium. Benign tumours can come for you too. Posts

If you are reading this I survived open heart surgery to remove a Myxoma from my left atrium. Benign tumours can come for you too. 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…

If you are reading this I survived open heart surgery to remove a Myxoma from my left atrium. Benign tumours can come for you too. Posts

I have returned to work after an unplanned excursion into the Australian health care system, including open-heart surgery. 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.My heart before surgery: Axial contrast-enhanced CT image of the chest demonstrating a large low-attenuation filling defect within the left atrium, subsequently identified as a left atrial myxoma. 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.1 AI tells me “High cholesterol is bad because it can lead to plaque building up in your arteries, which can narrow or clog them and reduce blood flow to your heart and other organs.” 2 I suspect strongly that Big Statin is trying to cover up the incidence of statin intolerance. But maybe I am just lucky.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).One of many hospital beds I occupied at Strathfield Private Hospital. This was I am sure pre-operation, though I think I had 4 different rooms over the 8 days I was there. Then the surgery, then intensive care, then cardiac ward, then regular ward.4 Calcium score of 50, consistent with mild 10-year estimated CVD risk. The burden of non-calcified plaque is estimated at 50% total plaque volume.5 There is also a Myxoma virus which gives Myxomatosis (tumors) to rabbits and is used for control. This is not that.6 It is estimated that fewer than 1 in a million people per year have surgery to remove a cardiac myxoma annually in Australia. I am even more lucky.7 Sure, I sometimes worked from home before COVID, back when doing so was less common, if going to campus wasn’t worth the trip. But much of my work involves a computer, and it isn’t as though the computer goes unvisited on weekends. Academics are nominally paid according to days and hours. I regard that as a legacy of archaic work rules imposed by the backwards labour arrangements of a university system in which both labour and management seem adamant to retain the assembly-line model of production. I regard myself as a professional. I work for outputs rather than inputs, and hope to be assessed that way as well. If I can produce the same output with fewer inputs, that should be regarded as an improvement in productivity, not evidence that somebody has failed to extract enough hours from me or enough dollars from funders, academia is irretrievably broken and there is a long chain of university administrators who bear responsibility. FIN Read more