TRANSPORTIST: OCTOBER 2021

How to value transport projects

Instead of measuring and monetising the fairy dust of `travel time savings’, a transport facility should be assessed on how much access it produces per unit of investmentAccess is the ease of reaching destinations. E.g. you might measure how many jobs (or restaurants or hospitals, etc.) can be reached in 30 minutes and/or $5 (or the dual of this measure, such as how many prospective patients an ambulance can reach in 12 minutes). A transport facility that increases access to destinations for a cost effectively is good. 

So the question is: does a streetcar or road or bike path enable people to reach more activities in less cost (time, money, aggravation, risk, negative externalities, etc.) than before, at a reasonable expenditure? (This cost includes the social and financial costs of building and providing the infrastructure). In short, are the upfront capital costsand ongoing maintenance and operations costs of the facility justified by the lower variable costs of its users? 

Sometimes (which is to say, often) transport projects are promoted for real estate. Real estate prices monetise the transport benefits (above what the user bears in time, money, and effort) in land value (time savings are not actually money, they become money through land value). We can build models that estimate the real estate value provided by additional accessibility.

So a better way of assessing the transport benefits is through real estate price uplift, as the market captures how people value the transport benefit. (We cannot simply add land prices to travel time and travel cost reductions, as that would be double counting). Places with higher access, and where access is more valuable, are more expensive and more productive and pay higher wages. We don’t really need to understand the detailed market mechanisms, nor attribute costs to detailed categories, the land market tells us how much access is worth, and transport models tell us how much access is created by a change to the network – from those two facts we can estimate the value created.

Because many projects are promoted by real estate interests, who presumably believe they will get the monetized benefits of those projects through higher land values, the public has a reasonable expectation that those interests pay for the costs of the project (that is, the tax incidence falls on the land owner). There are a variety of approaches, generally lumped as value sharing or value capture. The most general of these, a land value tax, originally promoted by Henry George, captures all of the uplift caused by all the access created by both transport investments and changes in the distribution of human activities.

From a project assessment point-of-view, land value uplift has often been part of the ‘wider economic benefits‘, which are optionally added after the value of travel time savings, which is considered the main benefit. ATAP for instance writes:

WEBs are improvements in economic welfare associated with changes in accessibility or land use that are not captured in traditional cost–benefit analysis (CBA). They arise from market imperfections, that is, prices of goods and services differing from costs to society as a whole. Reasons include economies of scale and scope, positive externalities, taxation and imperfect competition.

The international literature to date has concentrated on four types of WEBs that arise from major transport initiatives.

– WB1: Agglomeration economies — productivity gains from clustering by firms

– WB2: Labour market and tax impacts — productivity gains accruing to governments via the taxation system

– WB3: Output changes in imperfectly competitive markets — profit increases for firms

– WB4: Change in competition — gains to consumers and more efficient production.

ATAP goes on to write: 

“WEBs are only likely to be significant, and so worth estimating, for sizeable transport initiatives located in or improving access to large urban areas”

This logic is backwards. Because of induced demand, road projects rarely actually ‘save time’. Transit is often slower than car, so creating a project that induces someone from car to transit also doesn’t save time, but must nevertheless be preferred if people voluntarily switch.

Yet despite not ‘saving time’, these projects do create economic value. From a consumer perspective for instance, people can find a better fit for housing in the same travel effort (and may prefer to ride passively than to drive), or can engage in shopping activities that better match their desires in the same time window. From a producers perspective, WB1-WB4 from above are all embedded in land value. 

In reality, WEBs are the benefits of transport. If there were no productivity gains from clustering, we would not have cities and instead choose to be maximally spread out, and not need to be proximate in any sense. If there were no gains to consumers from competition, everyone would pay monopoly prices for everything, etc.

And these WEBs do not show up in ‘travel time savings’ but consistently show up in land value (CBDs are more expensive than suburbs are more expensive than rural areas). The WEBs are implicit in the land value uplift which occurs as a result the increased access. ‘Wider economic benefit’, properly measured as land value gains due to increased access, can and should be considered the primary benefit of new investment, not a speculative add-on aimed at juicing the numbers.

The consequence of properly and completely valuing benefits and full costs systematically may very well be a higher benefits estimate than a travel time savings-dominated metric would produce, which, if decision-making were rational, would justify more construction of public and active transport than would otherwise take place. A tax system that captured the land value that was thus created could relax whatever financing constraints currently limit that investment.

Jobs

Research

  • Wu, Hao, and Levinson, D. (2021) The Ensemble Approach to Forecasting: A Review and Synthesis. Transportation Research part C. Volume 132, 103357 [doi
    • HIGHLIGHTS
      • Review and synthesize methods of ensemble forecasting with a unifying framework.
      • As decision support tools, ensemble models systematically account for uncertainties.
      • Ensemble methods can include combining models, data, and ensemble of ensembles.
      • Transport ensemble models have the potential for improving accuracy and reliability.
      ABSTRACT: Ensemble forecasting is a modeling approach that combines data sources, models of different types, with alternative assumptions, using distinct pattern recognition methods. The aim is to use all available information in predictions, without the limiting and arbitrary choices and dependencies resulting from a single statistical or machine learning approach or a single functional form, or results from a limited data source. Uncertainties are systematically accounted for. Outputs of ensemble models can be presented as a range of possibilities, to indicate the amount of uncertainty in modeling. We review methods and applications of ensemble models both within and outside of transport research. The review finds that ensemble forecasting generally improves forecast accuracy, robustness in many fields, particularly in weather forecasting where the method originated. We note that ensemble methods are highly siloed across different disciplines, and both the knowledge and application of ensemble forecasting are lacking in transport. In this paper we review and synthesize methods of ensemble forecasting with a unifying framework, categorizing ensemble methods into two broad and not mutually exclusive categories, namely combining models, and combining data; this framework further extends to ensembles of ensembles. We apply ensemble forecasting to transport related cases, which shows the potential of ensemble models in improving forecast accuracy and reliability. This paper sheds light on the apparatus of ensemble forecasting, which we hope contributes to the better understanding and wider adoption of ensemble models.
    • This paper is the first dissertation paper from Dr. Hao Wu’s Dissertation: Theory of Ensemble Forecasting – with Applications in Transport Modeling. Hao successfully defended last month. It’s hugely important for changing how modeling is done, instead of relying on the one best model, an ensemble of models is more accurate and more reliable. Transport modeling has spent decades developing advanced (and Nobel prize-winning) methods, but has fetishised a single model approach rather than embracing uncertainty and humility. This needs to change. [Hao is also, as far as I know, the first Transport Engineering PhD from the University of Sydney since JJC Bradfield, who designed the Harbour Bridge and the Sydney Trains network] “In 1924, Bradfield was awarded the degree of Doctor of Science (for a thesis titled “The city and suburban electric railways and the Sydney Harbour Bridge”, the first doctorate in engineering awarded by the University of Sydney.”
  • Allen, Jeff, Farber, Steven, Greaves, Stephen, Clifton, Geoffrey, Wu, Hao, Sarkar, Hao, and Levinson, D. (2021) Immigrant Settlement Patterns, Transit Accessibility, and Transit Use. Journal of Transport Geography. 96, 103187 [doi]
    • ABSTRACT: Public transit is immensely important among recent immigrants for enabling daily travel and activity participation. The objectives of this study are to examine whether immigrants settle in areas of high or low transit accessibility and how this affects transit mode share. This is analyzed via a novel comparison of two gateway cities: Sydney, Australia and Toronto, Canada. We find that in both cities, recent immigrants have greater levels of public transit accessibility to jobs, on average, than the overall population, but the geography of immigrant settlement is more suburbanized and less clustered around commuter rail in Toronto than in Sydney. Using logistic regression models with spatial filters, we find significant positive relationships between immigrant settlement patterns and transit mode share for commuting trips, after controlling for transit accessibility and other socio-economic factors, indicating an increased reliance on public transit by recent immigrants. Importantly, via a sensitivity analysis, we find that these effects are greatest in peripheral suburbs and rural areas, indicating that recent immigrants in these areas have more risks of transport-related social exclusion due to reliance on insufficient transit service.
  • El-Geneidy, Ahmed and Levinson, D. (2021) Making Accessibility Work in Practice Transport Reviews (online first) [doi]
    • ABSTRACT: Accessibility, the ease of reaching destination, is the most comprehensive land use and transport systems performance measure (Levinson & Wu, 2020; Wachs & Kumagai, 1973; Wu & Levinson, 2020). Accessibility has been applied in planning research since the 1950s (Hansen, 1959), and still today, we find major barriers to adopting it in practice (Handy, 2020). Advances in computing and software have enabled researchers to generate complex measures of accessibility with higher spatial and temporal resolutions moving accessibility research at a fast pace, while the implementation of accessibility, in practice, lags (Boisjoly & El-Geneidy, 2017). Even simple measures, such as the cumulative opportunities measures of accessibility, confront challenges in adoption.

Videos

Research by Others

Polls

  1. How long must someone be dead before we should stop referring to them as “the late so and so”? (reading newspaper article describing the “late Erik Erikson”, dead 27 years.) Or should we say the late Isaac Newton?
    • <1 year 18.6%
    • 1-4 years 34.3%
    • 5-9 years 11.4%
    • >10 years 35.7%
    The median is just under 5 years, so I will go with that. 

News & Opinion

Dr. Hao Wu

Congratulations to Hao Wu for “satisfying the requirements for the award of the degree of Doctor of Philosophy at the University of Sydney.”

Thesis Title: Theory of Ensemble Forecasting – with Applications in Transport Modelling 

Lead Supervisor: Professor David Levinson.

Abstract:

Ensemble forecasting is a modeling approach that internalizes uncertainties, combining models with different assumptions or pattern recognition methods, data from different sources, and different methods of combining models. Compared to the prevalent single-model procedure, ensemble model predictions are more useful as decision support tools.

The use of ensemble forecasting has significantly improved forecast accuracy in weather forecasting, and is increasingly adopted in other fields. We find a lack of awareness, or application of ensemble models in transport, so the benefits of ensemble forecasting are not being realized.

In this research we establish a systematic framework for ensemble forecasting, and propose the `ensemble of ensembles’ to combine uncertainties in different ensemble methods. Ensemble models are applied to transport-related cases to examine the performance of different ensemble methods, and to compare ensemble models with single-model forecasts.

We find ensemble models can improve forecast accuracy by a notable degree beyond the best single model. Simple and weighted average ensemble models have mixed results. Meta-learner ensemble models provide significant improvement upon base models, but require sufficient training data to calibrate. We find the linear meta-learner to be robust and have good performance even with small training data. Ensemble of ensembles method combining different ways of combining models improves performance upon ensemble models, and generally has the best performance.

We conclude that ensemble models, if properly applied, are able to improve model performance. We posit that transport modeling can benefit enormously from the wider adoption, and awareness of ensemble forecasting methods. We hope that this research opens the door to methodically adopting ensemble models into transport modeling, that future transport research can build upon.

Hao Wu

The first journal article published from the dissertation is:

  • Wu, Hao, and Levinson, D. (2021) The Ensemble Approach to Forecasting: A Review and Synthesis. Transportation Research part C. Volume 132, 103357 [doi]

The Ensemble Approach to Forecasting: A Review and Synthesis

Recently published:

  • Wu, Hao, and Levinson, D. (2021) The Ensemble Approach to Forecasting: A Review and Synthesis. Transportation Research part C. Volume 132, 103357 [doi] [Author Link]
  • Highlights

    • Review and synthesize methods of ensemble forecasting with a unifying framework.
    • As decision support tools, ensemble models systematically account for uncertainties.
    • Ensemble methods can include combining models, data, and ensemble of ensembles.
    • Transport ensemble models have the potential for improving accuracy and reliability.

    Abstract

    Ensemble forecasting is a modeling approach that combines data sources, models of different types, with alternative assumptions, using distinct pattern recognition methods. The aim is to use all available information in predictions, without the limiting and arbitrary choices and dependencies resulting from a single statistical or machine learning approach or a single functional form, or results from a limited data source. Uncertainties are systematically accounted for. Outputs of ensemble models can be presented as a range of possibilities, to indicate the amount of uncertainty in modeling. We review methods and applications of ensemble models both within and outside of transport research. The review finds that ensemble forecasting generally improves forecast accuracy, robustness in many fields, particularly in weather forecasting where the method originated. We note that ensemble methods are highly siloed across different disciplines, and both the knowledge and application of ensemble forecasting are lacking in transport. In this paper we review and synthesize methods of ensemble forecasting with a unifying framework, categorizing ensemble methods into two broad and not mutually exclusive categories, namely combining models, and combining data; this framework further extends to ensembles of ensembles. We apply ensemble forecasting to transport related cases, which shows the potential of ensemble models in improving forecast accuracy and reliability. This paper sheds light on the apparatus of ensemble forecasting, which we hope contributes to the better understanding and wider adoption of ensemble models.

    Fig. 1. Methods of combining data and models.

    SUCE SEMINAR – The End of Traffic and the Future of Access

    I will be giving a seminar to the Sydney University Civil Engineers group today: Tuesday September 21, 2021 from 17:00 to 18:00 AEST. Zoom link for the seminar: https://uni-sydney.zoom.us/j/89457527160

    Title: The End of Traffic and the Future of Access

    Abstract:

    Two decades into the new millennium, transport is becoming interesting again. New technologies are taking root and society is responding; together, these phenomena are changing how people access places and exchange goods. This talk about the future of transport in cities discusses the implications of automation, electrification, sharing, and COVID-19 on travel demands and transport policy.

    Bio:

    Prof. David Levinson teaches at the School of Civil Engineering at the University of Sydney, where he leads the Network Design Lab and the Transport Engineering group. From 1999 to 2016, he served on the faculty of the University of Minnesota where he held the Richard P. Braun/CTS Chair in Transportation (2006-2016). Levinson has authored or edited several books, including The 30-Minute City: Designing for Access, The Transportation Experience, and Metropolitan Transport and Land Use: Planning for Place and Plexus, as well as numerous peer reviewed articles. He is the editor of the journal Findings.

    [UPDATE YouTube Link: https://www.youtube.com/watch?v=yx3WkiunkuY ]

    The End of Traffic and the Future of Access: A Roadmap to the New Transport Landscape. By David M. Levinson and Kevin J. Krizek.
    The End of Traffic and the Future of Access: A Roadmap to the New Transport Landscape. By David M. Levinson and Kevin J. Krizek.

    MULTIPLE POSITIONS – School of Civil Engineering, University of Sydney

    • Join a growing Faculty and be part of a University that places amongst the world’s best teaching and research institutions.
    • Located on the edge of Sydney’s bustling central business district, close to beaches, parks, public transport and shopping districts
    • Seeking outstanding Academics to provide leadership and help create a world-class, internationally recognised Faculty for research and education excellence

    About the opportunity 

    The School of Civil Engineering is at the forefront of civil engineering education and research. Our systems approach to teaching allows students to graduate with the much sought-after design, research and problem-solving skills needed to create and manage sustainable built and natural environments. 

    Our research strengths lie in structural engineering, geomechanics and materials, environmental fluid mechanics, transport engineering and complex systems. Our expertise and facilities continue to meet the issues associated with critical infrastructure, sustainability, climate change, water management and the natural environment.

    The School has a long tradition of engagement with industry which has led to successful collaborations with many leading national and global companies and government organisations.  This coupled with our excellence in analytical and experimental research has played a prominent role in the development of Australian and International Standards relating to many aspects of civil and structural design.

    The School of Civil Engineering at the University of Sydney is searching for faculty members at all ranks and in all areas of Civil Engineering. The school seeks to increase the diversity of its faculty and encourages women to apply.

    The School of Civil Engineering at the University of Sydney is prioritising a search for faculty members who are able to contribute in the areas of:

    • Environmental Fluid Mechanics
    • Transportation Engineering

    Click For More Details. [UPDATED LINK]

    The University of Sydney.

    Making Accessibility Work in Practice

    Recently Published:

    • El-Geneidy, Ahmed and Levinson, D. (2021) Making Accessibility Work in Practice. Transport Reviews [doi] [first 50 free download]

    Accessibility, the ease of reaching destination, is the most comprehensive land use and transport systems performance measure (Levinson & Wu, 2020; Wachs & Kumagai, 1973; Wu & Levinson, 2020). Accessibility has been applied in planning research since the 1950s (Hansen, 1959), and still today, we find major barriers to adopting it in practice (Handy, 2020). Advances in computing and software have enabled researchers to generate complex measures of accessibility with higher spatial and temporal resolutions moving accessibility research at a fast pace, while the implementation of accessibility, in practice, lags (Boisjoly & El-Geneidy, 2017). Even simple measures, such as the cumulative opportunities measures of accessibility, confront challenges in adoption.

    Immigrant Settlement Patterns, Transit Accessibility, and Transit Use

    Recently published:

  • Allen, Jeff, Farber, Steven, Greaves, Stephen, Clifton, Geoffrey, Wu, Hao, Sarkar, Hao, and Levinson, D. (2021) Immigrant Settlement Patterns, Transit Accessibility, and Transit Use. Journal of Transport Geography. 96 103187 [doi]
  • Abstract: Public transit is immensely important among recent immigrants for enabling daily travel and activity participation. The objectives of this study are to examine whether immigrants settle in areas of high or low transit accessibility and how this affects transit mode share. This is analyzed via a novel comparison of two gateway cities: Sydney, Australia and Toronto, Canada. We find that in both cities, recent immigrants have greater levels of public transit accessibility to jobs, on average, than the overall population, but the geography of immigrant settlement is more suburbanized and less clustered around commuter rail in Toronto than in Sydney. Using logistic regression models with spatial filters, we find significant positive relationships between immigrant settlement patterns and transit mode share for commuting trips, after controlling for transit accessibility and other socio-economic factors, indicating an increased reliance on public transit by recent immigrants. Importantly, via a sensitivity analysis, we find that these effects are greatest in peripheral suburbs and rural areas, indicating that recent immigrants in these areas have more risks of transport-related social exclusion due to reliance on insufficient transit service.

    Fig. 3. Bivariate maps of transit accessibility and density of recent immigrants.

    TRANSPORTIST: SEPTEMBER 2021

    Catbagger n. Someone who tries to put the cat back in the bag. I.e. someone attempting a futile act too late, which may have been prevented but cannot be reversed.

    In Australia are currently experiencing an exponential increase in COVID-19 cases as part of the Delta Wave. This is sad, and results in a few deaths daily (a rate, mind you, that is low enough other countries use it as a level at which lockdowns are lifted, rather than imposed). The rise is due to any number of mistakes that went previously. Iwon’t re-litigate the past. Instead, I posit that had those mistakes not been made at that time, lessons from those mistakes wouldn’t have been learned, and a similar mistake would have then been made shortly thereafter. This is not an apology for incompetence, and I am sure none of the Transportist readers would have made those mistakes had they been in charge, but is an acknowledgement that like COVID-19, incompetence is endemic and no one competent person can be everywhere simultaneously, and everyone relies on systems that are only as good as their weakest link.

    If not for some outbreak, people would not (over)-react, leaving the same conditions in place for a later outbreak. While on average one prefers to avoid mistakes, it is only by mistakes that lessons are learned, pre-planning is imperfect, and we can plan and prepare for any number of eventualities that would never occur at great cost, leaving us worse off than those who react to the eventualities that do actually occur without having wasted resources preparing for those that don’t.

    So while it may be psychologically or politically important to blame individuals who should have done this instead of that, or have learned from the mistakes of others, (and obviously the best people do better than the worst, by definition), and hopefully select slightly less incompetent administrators, that merely would have delayed the mostly inevitable outcome in terms of cases and deaths. And until there were COVID outbreaks, or very obvious prospects of COVID outbreaks, no vaccine would have been developed, no vaccine would have been manufactured, and no one would have gotten vaccinated, leaving everyone vulnerable to a COVID outbreak. 

    Posts

    Polls

    1. For authors, considering peer review: Are you biased so as to be more likely to accept papers that cite you? Are others (generally) similarly biased?
    • I am/Others are 46.3%
    • I am not/Others are 24.4%
    • I am/Others are not 0%
    • I am not/Others are not. 29.3%

    At least no one admitted to being more unethical than the population as a whole (choice 3). About half the people admitted bias (choice 1 and 3), indicating that the people who thought “Others are not” (choices 3 and 4) are hopelessly naive. I tend towards choice 2 for myself, at least I hope I am not.

    1. How much time would you be willing to sacrifice at the end of your life (your life would be X units of time shorter) to forego 1 month of lockdown for yourself?
    • 0-1 hour 44.4%
    • 1-24 hours 17.8%
    • 1-6 days 11.1%
    • 7 or more days 26.7%

    Now these are Twitter polls, so sampling bias is rife, and questions cannot be particularly sophisticated (lockdown means different things to different people in different places, what about lockdown for other people, etc.), but it does suggest that many people think that lockdown makes their life worse off in a way that suggests their benefits (reducing COVID cases) need to be countered with their costs (diminished quality of life). It also suggests that some other people really like lockdown, and if there had been negative numbers, some people who elected for choice 1 might have given up time at the end of their life to preserve lockdown longer. This I think gets pack to the Plants vs. Animals dichotomy I developed last year.

    Videos

    Conferences

    DAVID LEVINSON AWARD FOR BEST PAPER

    WSTLUR 2021 (PORTLAND)
    • Viewpoint: Turning streets into housing
      Adam Millard-Ball, University of California Los Angeles 
    HONORABLE MENTION BEST PAPER
    • The inevitability of automobility: how private car use is perpetuated in a Greenfield estate
      Jennifer Kent, University of Sydney 

    BEST STUDENT-LED PAPER 

    WSTLUR 2021 (PORTLAND)
    • Traffic-Land Use Compatibility and Street Design Impacts of Automated Driving in Vienna, Austria
      Emilia Brucke and Aggelos Soteropolis, Technical University of Vienna 
    HONORABLE MENTION BEST STUDENT-LED PAPER
    • Traffic Noise Feedback in Agent-Based Integrated Land-Use/Transport Models
      Nico Kuehnel (Technical University of Munich), Dominik Ziemke (Technical University of Dresden, and Rolf Moeckel (Technical University of Munich) 

    BEST PHD DISSERTATION

    WSTLUR 2021 (PORTLAND)
    HONORABLE MENTION BEST PHD DISSERTATION

    Research and Presentation

    Research

    Research by Others

    Jobs

    News & Opinion

    Post-graduate studies at the University of Sydney

    The University of Sydney Faculty of Engineering is running two events in Research Week aimed at recruiting prospective Higher Degree by Research Students. The event on September 9 has a breakout room led by Mohsen Ramezani discussing Transport Engineering.

    8 September 2021 – 1:00 pm AEST
    The Value of a PhD in Engineering, Computer Science or Project Management
    Associate Professor Kalina Yacef, Associate Dean Research Education

    Breakout rooms – Our Research

    • Aerospace, Mechanical and Mechatronic Engineering- Dr Donald Dansereau
    • Biomedical Engineering – Dr Omid Kavehei
    • Chemical and Biomolecular Engineering – Dr Farshad Oveissi & Professor Fariba Dehghani
    • Civil Engineering – Associate Professor Daniel Dias Da Costa & Associate Professor Yixiang Gan
    • Computer Science – Dr Shuaiwen Leon Song
    • Electrical and Information Engineering – Professor Xiaoke Yi
    • Project Management – Dr Nader Naderpajouh

    Admission, Scholarships and the Student Experience
    Lyndon McKevitt, Research Education Manager

    Registration – https://uni-sydney.zoom.us/webinar/register/WN_82bLLWm2QwOYqfPSgfnJ8A

    9 September 2021 – 7.00pm AEST
    The Value of a PhD in Engineering, Computer Science or Project Management
    Associate Professor Kalina Yacef, Associate Dean Research Education

    Breakout rooms – Our Research

    • Aerospace, Mechanical and Mechatronic Engineering – Professor Stefan Williams
    • Biomedical Engineering – Dr Omid Kavehei
    • Chemical and Biomolecular Engineering – Professor Fariba Dehghani
    • Civil Engineering – Dr Mohsen Ramezani
    • Computer Science – Dr Chang Xu & Dr Qiang Tang
    • Electrical and Information Engineering – Professor Xiaoke Yi & Dr David Boland

    Admission, Scholarships and the Student Experience
    Lyndon McKevitt, Research Education Manager

    Registration – https://uni-sydney.zoom.us/webinar/register/WN_yl-BsIj7Q2GNKj2uGIl5-w