Transportist: May 2021: Our aversion to risk will kill us.

Welcome to the latest issue of The Transportist, especially to our new readers. As always you can follow along at the or on Twitter

Hypothesis of the Month

This month’s hypothesis is that transit makes people more productive because they are time conscious.  Economies of agglomeration are often measured for cities. It is attributed to the interactions that people have and the access to other people (as well as machinery and other inputs to production). The source of this productivity has been associated with ‘ideas having sex’. Put more ideas together physically, and you will get more ideas out.

But there are other distinct aspects of places with agglomeration productivity externalties. These places differ from other types of places in that they are heavily dependent on public transport. One thing that daily public transport riders are keenly aware of is schedules. They lack the flexibility of other modes are they are time-dependent. And especially where frequencies are low (headways greater than every 5 minutes say, but certainly every 10 minutes), people time their approach to the station to arrive on-time and not be too early. This time-awareness must permeate other aspects of worklife more deeply, work has to get wrapped up or the bus or train will get missed. Procrastination faces its worst enemy, the deadline.

That said, I have not felt suddenly more productive since joining the ranks of daily transit users earlier this year. On the other hand, this newsletter has gotten longer. 


Speaking of time, Daylight Savings Time has ended for the parts of Australia that abided it. No daylight was saved. The Time Zone Map of Australia is absurdism at its finest. Leaving aside niche cases, South Australia is on the half-hour. Only the southern half of the country abides DST. Australia should just adopt Queensland’s time zone and be done with it.

Transportist Posts

[I am trying a new format this month, embedding the articles in the newsletter.]

  • Virus Transmission is an Accessibility Issue: Quarantine Sites Should be as Remote as Possible
    • Urban economists like to brag about how cities are more productive than other areas because of `economies of agglomeration’ which reduce the cost of physical contact, as people are closer together. The cost of that closeness is increased sharing of the air between people, and the airborne viruses that reside in it. Viruses physically move from one person to another. Just as the likelihood of interaction between two people is inversely proportional to the distance between them, the likelihood that viruses are transmitted between two people is inversely proportional to the distance between them, as the longer the virus is exposed to colder out-of-body temperatures and sunlight, the less likely it survives AND the nearer two people are, the sooner a virus can go from one person to another. This is just accessibility.So, putting people close together in hotels to quarantine them, assuming some have the virus, is obviously going to increase the likelihood of transmission between hotel residents compared with putting them farther apart in camps. And putting these hotels in cities is obviously going to increase the likelihood that a virus from the hotel interacts with the city around it.So if the intent is public health, quarantined people should be kept far from each other and from non-quarantined people.Fortunately Australia is a big country. There are many opportunities to quarantine people away from each other and away from others. Unfortunately, people are being quarantined in the middle of cities inside of hotels.The latest outbreaks in Sydney and Perth should not be surprising. That this was the policy in April of 2020, when everything was new would be understandable. That this remains policy in April of 2021 when it is not is puzzling.If quarantine sites were remote, and the likelihood of transmission reduced further, perhaps Australia could increase its intake of stranded citizens, international immigrants, and students.
    • [A simulation of a Virus on a Network from Northwestern]
    • [More than a dozen COVID leaks in 6 months …]
  • TransportLab Student Presentations at the 2020 TRANSW Symposium
  • One Big Chinese Lesson for America’s Infrastructure Plan It’s not just about laying down tracks for superfast trains
    • David Fickling at Bloomberg writes: One Big Chinese Lesson for America’s Infrastructure Plan It’s not just about laying down tracks for superfast trains. It’s about letting the public sector benefit from increasing land values.My quotes:Measures to levy fees on the local property owners, such as the special assessment zones used to finance projects like Seattle’s South Lake Union Streetcar, could in theory have a similar effect. The problem is that the unity of purpose needed to develop larger-scale infrastructure is lacking in the modern U.S., according to David Levinson, a professor of transport engineering at the University of Sydney and former transportation planner in Maryland.“Transportation decisions are much more fractured” in the U.S., Levinson says. “Property taxes are a local government thing whereas transport infrastructure funding tends to be a state thing. Governments aren’t willing to upend the privileges of municipalities to get infrastructure built.”That fragmentation also means that spending is too reactive — for instance, repeatedly widening roads to eliminate congestion rather than developing integrated visions for how cities as a whole could function better. “The traffic engineers have more power than the planners,” Levinson says, “and the decision makers drive a car, so they have the view from their windshield.”
  • Recent Research on Video: Lane Changing, Injury Severity, and Measuring Traffic from Moving Probes
    • Ang Ji, a PhD student at TransportLab, published 5 papers last year. He has created videos of presentations of those papers for those who prefer their narrative in YouTube format. You can see them at the VIDEO links below. Then you should read the article. [Note, you might have to adjust the volume up]
      1. Ji, Ang and Levinson, D. (2020) A Review of Game Theory Models of Lane ChangingTransportmetrica A. 16(3), 1628–1647. [doi] [VIDEO]
      2. Ji, Ang and Levinson, D. (2020) Estimating the Social Gap with a Game Theory Model of Lane Changing.  IEEE Intelligent Transportation Systems Transactions. [doi] [VIDEO]
      3. Ji, Ang and Levinson, D. (2020) An energy loss-based vehicular injury severity model. Accident Analysis and Prevention. 146 October 2020, 105730. [doi] [VIDEO]
      4. Ji, Ang and Levinson, D. (2020) Injury severity prediction from two-vehicle crash mechanisms with machine learning and ensemble models. IEEE Open Journal of Intelligent Transportation Systems. [doi] [VIDEO]
      5. Davis, Blake, Ji, Ang,  Liu, Bichen, and Levinson, D. (2020) Moving Array Traffic ProbesFrontiers in Future Transportation. doi: 10.3389/ffutr.2020.602356 [doi] [VIDEO]
  • Auto Buybacks: Cash for ICE – Accelerating the Transition to EVs (And AVs while we are at it)
    • One of the undiscussed features of transport electrification is the large number of internal combustion engine (ICE) vehicles that will remain on the road in the absence of prohibition. There are many stranded incumbents like service stations and their upstream suppliers who will continue to provide fuel for the remaining vehicles, and that fuel will have a lower and lower market price (sans taxes), as demand will have dropped and the supply will not, and existing producers will have huge incentives to pump fuel while it still has some market value. Consumers with older cars will be reluctant to replace their working vehicle when low fuel prices abound. Many just like their cars, and the smell of gasoline is an attractant for some.To accelerate the transition, governments will step in and buy back older cars for recycling. At first this will be voluntary, then it will be mandatory. Governments won’t simply confiscate property, that goes to far. Instead governments will refuse to register vehicles that pollute above some threshold, for instance, (a threshold that rises over time) and thereby keep those vehicles off public roads, only a few antiques will be permitted in the end, and then only for limited parades and displays. This will be the UK’s Scrappage Scheme or US’s Cash for Clunkers on steroids. Some back of the envelope math follows: There are say 300,000,000 cars in the US by the time this gets going. (There are 286 million now!). Assume all new vehicles, and 50% of extant vehicle are electric (so this is circa mid 2030s, since by 2025 most new cars will be EVs and by 2030 essentially all new cars will be EVs). There remain 150,000,000 ICE cars left. At ~$5,000 per used ICE car, that would be $750,000,000,000 ($750B). To be clear, $750B is apparently not what it used to be, and since it would probably have to be phased in over time (say 10 years), it is only $75B/year for 10 years. (Or ~$250 per US taxpayer, or less than $1/day for 10 years to pay for an accelerated all-electric fleet).I imagine this is implemented as $5,000 credit for trade-in toward an EV, but this would vary by vehicle of course, and rules would have to be in place about only registered and operational vehicles would be eligible to avoid paying for the wrecks in people’s garages or on their front lawns.Those turned in cars could be recycled, scrapped for parts, or converted if EV conversion technology becomes feasible, though I suspect recycling will be more cost-effective.This transition would have many environmental and economic stimulus benefits, since these remaining ICEs would, on average, be inside older more polluting vehicles. Whether this is economically worthwhile, or the best means to reduce carbon emissions, is another matter. However will this happen? Yes, in some form. The 2031 recession, or the 2037 recession at the latest will result in a program just like this.[Those new EVs, by the mid-2030s, will also be Level 4 AVs for all intents and purposes, so this has numerous other safety benefits].



  • Wu, Hao and Levinson, D. (2021) Optimum Stop Spacing for Accessibility. European Journal of Transport and Infrastructure Research. 21(2) 1-18 [doi]The cumulative opportunities measure accessibility is defined as the number of opportunities reachable under a given time threshold. The spacing between transit stations is fundamental for accessibility by transit, yet the stations cannot be easily relocated in built-up areas. This paper examines the relation between transit stop spacing and person-weighted accessibility for an urban train route through an analytical model, and identifies that for each type of transit (e.g. given some combination of vehicle acceleration, deceleration, top speed, dwell time, platform type), an optimal stop spacing exists that maximizes accessibility; neither short nor excessive stop spacing are efficient in providing accessibility. Rail is used as example, though the model and findings are applicable to bus services as well. This paper brings attention to the importance of stop spacing in accessibility, and provides guidelines for transit planning for the operational improvement of transit accessibility.


  • 42ND AUSTRALASIAN TRANSPORT RESEARCH FORUMThe ATRF Executive Committee and the ATRF 2021 Local Organising Committee are pleased to announce that the 42nd Australasian Transport Research Forum will be held at the Queensland University of Technology in Brisbane on 8-10 December 2021.[I am on the Scientific Committee this year]


  • Advanced Introduction to Urban Transport Planning
    • by Kevin J. Krizek and David A. King
    • Publication Date: May 2021 ISBN: 978 1 80037 408 9 Extent: 160 pp
    • Insightful and original in its approach, this Advanced Introduction to Urban Transport Planning provides a fresh look at cost-efficiency and casts the craft of transport planning in new light, allowing engineers and urban planners to understand the benefits of breaking mobility-centric systems that favour cars and prioritising multi-modal transport systems that promote access. It features in-depth analysis of traditional methods and how these are changing due to new technologies, financial constraints and evolving environmental trends.


Urban Findings is launching soon. We are plotting Energy Findings now. If you are interested, let me know. The journal continues to solicit articles of under 1000 words that have clear research questions, methods, and findings.

  • Alattar, Mohammad Anwar, Caitlin Cottrill, and Mark Beecroft. 2021. “Accounting for Spatial Heterogeneity Using Crowdsourced Data.” Findings, April.
  • Lokesh, Kadambari, and Greg Marsden. 2021. “Estimates of the Carbon Impacts of Commute Travel Restrictions Due to COVID-19 in the UK.” Findings, April.

Research by Others


  • Martin Wachs (1941-2021) passed earlier this month. UCLA’s ITS has more details. I met Marty when he applied to join the University of California at Berkeley and I was on the student search committee. He arrived too late to serve on my committee or as a formal advisor (though now doubt had he been a year or two earlier, or I a year or two later, that would have happened). Though he was not a formal advisor, he did advise me, especially as I entered the very frustrating academic job market. Our paths have crossed numerous times, and I was honoured in 2019 to give the Marty Wachs Distinguished Lecture at UCLA. Despite our generational differences, he is in some ways an academic brother, as his advisor at Northwestern was Bill Garrison, from whom I took classes later collaborated. In addition to being a fixture in transport planning for decades, and an academic and personal advisor to many, his scientific contributions in the realm of equity, transport and the elderly, and measuring access, including developing and applying the now widely used cumulative opportunities metric of accessibility, are important. He will be sorely missed.

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