The Healthiest vs. Greenest Path: Comparing the Effects of Internal and External Costs of Motor Vehicle Pollution on Route Choice 

On-road emissions, a dominant source of urban air pollution, damage human health. The ‘healthiest path’ and the ‘greenest path’ are proposed as alternative patterns of traffic route assignment to minimize the costs of pollution exposure and emission, respectively. As a proof-of-concept, the framework of a link-based emission cost analysis is built for both internal and external environmental costs and is applied to the road network in the Minneapolis – St. Paul Metropolitan Area based on the EPA MOVES and RLINE models. The healthiest and the greenest paths are skimmed for all work-trip origin-destination pairs and then aggregated into work trip flows to identify the healthier or greener roads in a comparative statics analysis. The estimates show that highways have higher emission concentrations due to higher traffic flow, on which, but that the internal and external emission costs are lower. The emission cost that commuters impose on others greatly exceeds that which they bear. In addition, the greenest path is largely consistent with the traditional shortest path which implies that highways tend to be both greener and shorter (in travel time) for commuters than surface streets. Use of the healthiest path would generate more detours, and higher travel times.
Route choice, Traffic assignment, Shortest path, Pollution, Emissions, Exposure, Intake

Warranties and Indemnities …

In this post I compare the digital conservancy/repository terms of service for two universities: Minnesota and Sydney.

The University of Minnesota Digital Conservancy I have used for a few years. It is well run and the staff are helpful.

The University of Minnesota:

There is one last step: In order for The UDC to reproduce, translate and distribute your submission worldwide, you must agree to the following terms. If you have questions regarding this agreement, please contact the Digital Conservancy staff:

By depositing this Content (“Content”) in the University Digital Conservancy (“Digital Conservancy”), I agree that I am solely responsible for any consequences of uploading this Content to the Digital Conservancy and making it publicly available, and I represent and warrant that:

I am either the sole creator and the owner of the copyrights and all other rights in the Content; or, without obtaining another’s permission, I have the right to deposit the Content in an archive such as the Digital Conservancy.

To the extent that any portions of the Content are not my own creation, they are used with the copyright holder’s express permission or as permitted by law. Additionally, the Content does not infringe the copyrights or other intellectual property rights of another, nor does the Content violate any laws or another’s rights of privacy or publicity.

The Content contains no restricted, private, confidential, or otherwise protected data or information that should not be publicly shared.

I understand that the Digital Conservancy will do its best to provide perpetual access to my Content. In order to support these efforts, I grant the Regents of the University of Minnesota (“University”), through its Digital Conservancy, the following non-exclusive, perpetual, royalty-free, world-wide rights and licenses:

to access, reproduce, distribute and publicly display the Content, in whole or in part, in order to secure, preserve and make it publicly available, and

to make derivative works based upon the Content in order to migrate the Content to other media or formats, or to preserve its public access.

These terms do not transfer ownership of the copyright(s) in the Content. These terms only grant to the University the limited license outlined above.

In contrast the University of Sydney eScholarship Repository is far less friendly in terms of licenses.

Sydney eScholarship Distribution License

There is one last step: In order for Sydney eScholarship to reproduce, translate and distribute your submission worldwide, your agreement to the following terms is necessary. Please take a moment to read the terms of this license, and click on one of the buttons at the bottom of the page. By clicking on the “Grant License” button, you indicate that you grant the following terms of the license.

Not granting the license will not delete your submission. Your item will remain in your “My Sydney eScholarship” page. You can then either remove the submission from the system, or agree to the license later once any queries you might have are resolved.

By this License, the Contributor, for the benefit of the University,
grants the University following rights.

1.	Definitions
Contributor means the author.contributor identified in the Sydney 
eScholarship Repository Metadata.

eScholarship Repository Metadata means the metadata encoded in the 
uploaded Works by the Contributor when accessing the Sydney 
eScholarship Repository.

University means The University of Sydney acting through Sydney 
eScholarship Repository, a body corporate under the University of 
Sydney Act 1989, ABN 15 211 513 464, of University of Sydney Library 
F03 University of Sydney, NSW 2006  Sydney  NSW  2006.

Work means the works listed [as Titles in the Sydney 
eScholarship Repository Metadata/in the Schedule to this License].

2.	Licence
The Contributor grants the University the non-exclusive perpetual 
license to reproduce and communicate the Work to the public via the 
Sydney eScholarship Repository and, without changing the content, to 
translate the Work to any medium or format for the purposes of 
preservation, research and study provided such use is not for a 
commercial purpose,  The Contributor also agrees that the University 
may keep more than one copy of the Work for the purposes of security, 
backup and preservation.

3.	Attribution
The eScholarship Repository will clearly identify the Contributor as 
the author of the Work.

4.	Acknowledgements
The Contributor acknowledges that:
(a)	they will not receive any payment from the University for the
 grant of rights under this License;
(b)	the Work is subject to the approval of the University and may
 not be accepted to the eScholarship Repository;
(c)	the University may remove the Work from the eScholarship 
Repository at any time at its absolute discretion; and
(d)	they have no termination rights under this License.

5.	Standard of work
In order for Work to be accepted to and remain on the eScholarship 
Repository, the Contributor acknowledges that:
(a)	the Work is academic and postgraduate (unless Work is an 
Honours Thesis or is otherwise approved by the University in writing)
; and
(b)	text material submitted is final draft or published version, 
and non-text material submitted is in its final form.

6.	Warranties
The Contributor warrants that:
(a)	the Work is their original work;
(b)	they have obtained consents in writing from all previous
publishers of the Work to enter into this License;
(c)	they have obtained consents in writing from third parties
which have any materials reproduced in the Work to publish the Work;
(d)	they can grant the rights under this License and the
University's exercise of those rights will not infringe the
copyright or other intellectual property rights of third parties;
(e)	to the best of their knowledge, the Work is accurate as at
the date in which the final version of the Work is submitted to the
University and as far as reasonably possible they have sought to
verify all statements in the Work which purport to be true and
(f)	to the best of their knowledge, the Work does not contain any
 scandalous, defamatory, or obscene material or any material which is
  actionable for interference with privacy, infringement of copyright,
  breach of confidence, passing off or contravention of any other
  private right; and
(g)	they have not engaged in any practices in preparing the Work
that would amount to plagiarism or any other form of academic
dishonesty or research misconduct under University policies and rules
 or which would (or would be likely to) bring the Contributor or the
 University into disrepute, and that they have complied with the
 University's policies, procedures and rules.
(h)	where the work is a thesis, it is a direct equivalent of the
final officially approved version that was submitted, and no
emendation of content has occurred other than minor variations in
formatting, that are the result of the conversion to digital format.

7.	Breach of warranty
The Contributor agrees to:
(a)	notify the University as soon as they become aware of any 
circumstances relating to the breach or potential breach of a 
warranty in clause 6;
(b)	allow the eScholarship Repository Coordinator to take any 
action to manage the University's exposure to such liability;
(c)	provide the University with all reasonable assistance in 
relation to the conduct or defence of any legal proceedings which may
 be commenced by or against the University in relation to the breach 
 of a warranty in clause 6; and
(d)	indemnify the University against any actions, costs or 
expenses arising out of the breach of a warranty in clause 6.

8.	Jurisdiction
The Contributor agrees that this License is governed by the law of 
New South Wales, submits to the non-exclusive jurisdiction of the 
courts in New South Wales and waives any right they have to object to
 an action being brought in those courts (including by claiming that 
 the action has been brought in an inconvenient forum or that those 
 courts do not have jurisdiction).
Note especially Clause 7.
“(d) indemnify the University against any actions, costs or expenses arising out of the breach of a warranty in clause 6.”
Why exactly would I agree to this? I assume it only applies if they lose (i.e. if a court rules a warranty has been breached), but even so, who really knows. As a general rule a university should be indemnifying its academic staff, not vice versa.
The University of Sydney libraries seem to have a much smaller repository.

The Transportist: August 2017

 Indifference Bands for Route Switching.

Printed, (after more than a year in “online first” purgatory) and now available for FREE Viewing.11116_2016_9699_Fig3_HTML

Abstract: The replacement I-35W bridge in Minneapolis saw less traffic than the original bridge though it provided substantial travel time saving for many travelers. This observation cannot be explained by the classical route choice assumption that travelers always take the shortest path. Accordingly, a boundedly rational route switching model is proposed assuming that travelers will not switch to the new bridge unless travel time saving goes beyond a threshold or “indifference band”. To validate the boundedly rational route switching assumption, route choices of 78 subjects from a GPS travel behavior study were analyzed before and after the addition of the new I-35W bridge. Indifference bands are estimated for both commuters who were previously bridge users and those who never had the experience of using the old bridge. This study offers the first empirical estimation of bounded rationality parameters from GPS data and provides guidelines for traffic assignment.


Bounded rationality, Indifference band, Empirical estimation, GPS study, Route Choice


Roderick Distinguished Lecture

Rodd Staples, Northwest Rail Link
Rodd Staples, Northwest Rail Link

Roderick Distinguished Lecture

Thursday 31 August 2017

Join us on Thursday 31 August 2017 for the second Roderick Distinguished Lecture for 2017 featuring the Sydney Metro Program Director for Transport for NSW, Mr Rodd Staples. presenting an insight into the Sydney Metro project, his path to such a role and the opportunities available for civil and other engineering graduates to help deliver the transport infrastructure required of a modern city.

Sydney Metro is Australia’s biggest public transport project, with 31stations and 66km of new metro rail.

This project comes at a time of the launching of the Transportation Engineering major within the Faculty of Engineering & IT, which provides students with the opportunity to embrace the mathematical and engineering methods required to plan, design, operate and manage the infrastructure necessary to achieve safe, economical and environmentally sustainable movement of people and goods.

Professor David Levinson who has recently joined the School to lead the implementation of this new major, sees it as an exciting time to be in a city where there is currently a generation’s worth of major transport infrastructure projects occurring simultaneously.


Rodd has almost twenty years experience in transport and infrastructure, across both government & private sectors. With tertiary qualifications in civil engineering & finance, Rodd has worked across a mix of senior executive, project management & technical leadership roles with a core career focus on transport project planning, development and delivery.

“The opportunity to work on a city-transforming project with such a dedicated team is a privilege and one that I am very proud of,” Rodd says.

“We are delivering a new metro system with the customer as its focus which will help transform public transport in Sydney.”


Thursday 31 August 2017

Open from 5:00 for 5:30pm start, followed by refreshments and networking from 6:30pm


PNR Lecture Theatre No 2, Faculty of Engineering & IT, University of Sydney


This event is free but please CLICK HERE to register or contact Malcolm Boyd (see details overleaf)


The Roderick Distinguished Lecture Series

The Roderick Distinguished Lecture Series brings the leaders of industry and government to the University to present to the civil engineers of tomorrow the challenges and opportunities which they and their organisations face and the role that civil engineering plays in their work environment

The Roderick Lectures are an initiative of the Council for Civil Engineering Sydney, an industry advisory group formed to assist the School of Civil Engineering to deliver world-class education and research through an inclusive program of engagement between industry and academia at all levels.

The Roderick Lectures are promoted widely to the students as well as the industry network of the School of Civil Engineering

The Roderick Lecture series acknowledges Professor Jack William Roderick who, as Head of School from 1951 to 1978, initiated programs of engagement with industry to build and to augment the teaching and research programs of the School through the Graduates Association and the Civil Engineering Foundation.

For more information

Malcolm Boyd| Executive Officer | Council for Civil Engineering Sydney
T 0412 797 479 | E

Specialists say parking shortfalls for Hornsby and Ku-ring-gai commuters will require wide range of solutions

I was interviewed by Jake McCallum of the Hornsby Advocate (part of the Telegraph family) for the article: “Specialists say parking shortfalls for Hornsby and Ku-ring-gai commuters will require wide range of solutions” My quotes below:

University of Sydney Civil Engineering specialist, Professor David Levinson said “while having fast, direct, frequent, and reliable public transport service is important, being able to get to that service is critical”.

“Governments shouldn’t shy away from cheap, effective forms of transport to train stations,” he said.

Large scale bike parking could be the answer to fix commuter parking woes.

Mr Levinson said he was shocked at Ku-ring-gai Council’s estimates of costs to cure parking shortfalls.

“Rather than focusing on plans that see $200 million used to fund the development of 2600 parking space, we should be looking into the feasibility of large scale bicycle racks as a form of commuter parking,” Prof Levinson said. “It [parking] is not the best use of public capital.”

Hornsby Council and Hornsby state Liberal MP Matt Kean did not make submissions to the parliamentary inquiry. However, Mr Kean said he was proud to have delivered 42 extra car spaces at Asquith station.

“My focus now is doubling capacity of the carpark at Hornsby station,” he said.

This follows up on my Parliamentary submission on Commuter Car Parking.

Measuring Winners and Losers from the new I-35W Mississippi River Bridge | FREE Viewing

Finally printed, (after more than a year in “online first” purgatory presumably WinnerLoser_ByO_2accumulating citations so the journal can juice it’s impact factor) now available for FREE Viewing, but not downloading, thanks to the new initiative below. While not perfect, this seems a reasonable step on the path towards full open-access.


Springer nature 2x Shared it

Dear Author,

Congratulations on publishing “Measuring winners and losers from the new I-35W Mississippi River Bridge” in Transportation. As part of the Springer Nature SharedIt initiative, you can now publicly share a full-text view-only version of your paper by using the link below. If you have selected an Open Access option for your paper, or where an individual can view content via a personal or institutional subscription, recipients of the link will also be able to download and print the PDF. All readers of your article via the shared link will also be able to use Enhanced PDF features such as annotation tools, one-click supplements, citation file exports and article metrics.

We encourage you to forward this link to your co-authors, as sharing your paper is a great way to improve the visibility of your work. There are no restrictions on the number of people you may share this link with, how many times they can view the linked article or where you can post the link online.

More information on Springer Nature’s commitment to content sharing is available here.

Springer Nature

The Springer Nature SharedIt Initiative is powered by ReadCube technology.

Kristin Carlson: Accessibility Impacts of Bus Access to Managed Lanes

Congratulations to Kristin Carlson for successfully defending her MS Thesis: “Accessibility Impacts of Bus Access to Managed Lanes” at the University of Minnesota Department of Civil, Environmental, and Geo- Engineering on August 22, 2017. The thesis will be made publicly available soon.

Figure 15: The absolute di↵erence in average job accessibility between the ML test scenario and baseline within 30 minutes by transit from 7 - 9 AM on Wednesday, October 5, 2016.
Figure 15: The absolute difference in average job accessibility between the ML test scenario and baseline within 30 minutes by transit from 7 – 9 AM on Wednesday, October 5, 2016.

This research introduces a method to measure changes in transit accessibility resulting from adjustments in bus-highway interactions. Operational differences between general purpose (GP) and managed lanes (ML) are measured using average travel time. Changes to transit travel time are systematically introduced to General Transit Feed Specification (GTFS) data through the use of the StopTimesEditor computer program developed for the purpose of this analysis. The methodology is tested on two express bus routes in the Minneapolis – St. Paul region (Twin Cities). The change in operating speed along portions of the selected transit routes is translated to changes in the job accessibility of the surrounding communities. The percent change in the worker-weighted average job accessibility for the area surrounding the transit routes and for the entire metropolitan region are 12% and 0.25% respectively. The methods introduced in this study can be used to evaluate the accessibility impacts of different highway operating environments for buses, or estimate the accessibility outcomes of different bus-highways scenarios.

Dr. Jessica Schoner: Mutually Reinforcing Relationships Between Bicycling Infrastructure

Jessica Schoner
Jessica Schoner

Congratulations to soon-to-be Dr. Jessica Schoner for successfully defending her dissertation: ‘Mutually Reinforcing Relationships Between Bicycling Infrastructure’ before a standing room only crowd at the University of Minnesota campus on 21 August 2017.



Theory slide. Source: Schoner, J (2017) Mutually Reinforcing Relationships Between Bicycling Infrastructure
Theory slide. Source: Schoner, J (2017) Mutually Reinforcing Relationships Between Bicycling Infrastructure

Researchers have long sought evidence about whether dedicated bicycling infrastructure induces people to cycle, based on a supply-driven assumption that providing infrastructure causes the behavior change. However, supply inducing demand is only one of four theoretical relationships between bicycling and infrastructure. The aims of this research are twofold:

  1. Develop a theoretical framework to identify and evaluate all of the possible relation- ships between bicycling and infrastructure and describe how these factors reinforce one another to shape diffusion of bicycling and infrastructure in cities; and
  2. Develop and execute a research plan to empirically model selected hypotheses within the theoretical framework.

The empirical portion of the dissertation tests the hypotheses that (1) bicycling infrastructure supply induces bicycling demand, and (2) bicycling demand induces additional demand. The research uses a series of cross-sectional tests at multiple points in time as well as lagged variable models to add a layer of temporal precedence to our otherwise cross-sectional understanding of associations between bicycling and infrastructure. The findings show persistent associations between infrastructure and bicycling over time, across geographies, and at both the individual and aggregate level. The association between bicycling and additional bicycling holds over time at the individual household level and for bike share membership. However, the tests failed to find evidence of bike share stations and activity affecting general population cycling rates.
This dissertation provides a roadmap for future research into feedback loops between bicycling and infrastructure. It additionally provides practitioners with guidance on both the strengths and limitations of both infrastructure provision and socially-focused bicycling initiatives.

Like most bicycling research, this dissertation is limited by the quality of data available for both bicycling behavior and infrastructure supply. Neither the data nor the tests performed are rigorous enough to infer causality; instead, the findings add strength and nuance to the existing body of literature.

Papers related to the dissertation are available at:

  • Schoner, Jessica and David Levinson (2014) The Missing Link: Bicycle Infrastructure Networks and Ridership in 74 US Cities. Transportation 41(6) 1187-1204. [doi]
  • Schoner, Jessica, Greg Lindsey, and David Levinson (2016)  Is Bikesharing Contagious? Modeling its effects on System Membership and General Population Cycling.  Transportation Research Record: Journal of the Transportation Research Board. 2587 pp. 125-132. [doi]
  • Schoner, J., & Lindsey, G. (2015). Differences Between Walking and Bicycling over Time: Implications for Performance Management. Transportation Research Record: Journal of the Transportation Research Board, (2519), 116-127. [doi]
  • Schoner, J, Lindsey, G., and Levinson, D. (2014) Factors Associated with the Gender Gap in Bicycling Over Time. Presented at Transportation Research Board Annual Meeting 2015.

The final dissertation will be posted online soon.

As every good dissertation should, it raises as many questions as it answers, and if you are looking for a topic, there are strong research opportunities available to test Hypotheses 2 and 4 on the effect of bicycling demand on infrastructure, and infrastructure momentum. There are also opportunities to examine the new stationless bike sharing systems that are emerging in China (and Australia, and elsewhere) regarding Hypothesis 3 and social diffusion.


Some other bicycling research led by the newly minted Dr. Schoner includes:

The paper from her MS Thesis is available here:

  • Schoner, Jessica, Xinyu (Jason) Cao, and David Levinson (2015) Catalysts And Magnets: Built Environment Effects On Bicycle Commuting. Journal of Transport Geography 47 100–108. [doi]