Transportist: June 2021


  • Hao Wu, Paolo Avner, Genevieve Boisjoly, Carlos K. V. Braga, Ahmed El-Geneidy, Jie Huang, Tamara Kerzhner, Brendan Murphy, Michał A. Niedzielski, Rafael H. M. Pereira, John P. Pritchard, Anson Stewart, Jiaoe Wang, and David Levinson (2021) Urban access across the globe: an international comparison of different transport modes. NPJ Urban SustainabilityVol. 1, Article 16 [doi]

Access (the ease of reaching valued destinations) is underpinned by land use and transport infrastructure. The importance of access in transport, sustainability, and urban economics is increasingly recognized. In particular, access provides a universal unit of measurement to examine cities for the efficiency of transport and land use systems. This paper examines the relationship between population-weighted access and metropolitan population in global metropolitan areas (cities) using 30-minute cumulative access to jobs for 4 different modes of transport; 117 cities from 16 countries and 6 continents are included. Sprawling development with intensive road network in American cities produces modest automobile access relative to their sizes, but American cities lag behind globally in transit and walking access; Australian and Canadian cities have lower automobile access, but better transit access than American cities; combining compact development with an intensive network produces the highest access in Chinese and European cities for their sizes. Hence density and mobility co-produce better access. This paper finds access to jobs increases with populations sublinearly, so doubling metropolitan population results in a less than double access to jobs. The relationship between population and access characterizes regions, countries and cities, and significant similarities exist between cities from the same country.

Transportist Posts

We often talk about networks providing connection. The World Wide Web is a network that connects people with websites across the world. But interesting word “web”, it is appropriated from a spider’s “web“, which has lots of strands that connect internally and to external supports, and enable the spider to move quickly over space. But the spider “web’s” primary purpose is to tangle up the wayward insect that crosses its path and prevent it from traveling further. That meaning of the word comes from a further word describing woven fabrics, weaving, and tapestry. Weaving of clothes is of course aimed at preventing cold air from reaching the body and provides insulation.

We could look at the word “net”, it is appropriated from a fisherman’s net. “Open textile fabric tied or woven with a mesh for catching fish, birds, or wild animals alive; network; spider web,” also figuratively, “moral or mental snare or trap.” So it too has the connotation of restricting movement rather than facilitating it.

Ther term “grid” comes from griddle, a device for keeping things from falling into the fire (while spreading heat along its elements).

Building frames are types of networks to transmit force between the structure and the earth to provide support. But these supports are rigid and generally prevent going through them, requiring people to go around. Normally this isn’t a big deal in a steel frame building, where the supports take a minimum of space, but in masonry or wood structures, the supports are pretty coterminous with walls, and individuals must find doors for passage. The walls and ceilings themselves, like woven clothing, protect the occupant from the vagaries of the environment. 

Modern transport networks have much the same features as a spider’s web. Roadways are designed to facilitate movement for cars while trapping pedestrians who want to cross the street. Cars don’t literally eat pedestrians, but this environment certainly reduces the number of pedestrians, as people who would otherwise walk give up and join the motoring majority. We might say automobility eats walk mode share.

Wired power networks impose their own constraints. High voltage power lines are not to be touched, for instance. But they occupy little space. They do require the clearance of trees, disconnecting the dense bush in places, for the benefit of users of long-distance electricity. Power boxes often interrupt footpaths (needlessly).

Wired communications networks don’t have the same voltages, but still have physical constraints. Boxes for communications need to be accessed, leading to works in the transport network.

The disconnection wrought by communications may be more intangible. For every minute someone is engaged with distant people online (or even colleagues two desks away), they are not engaged with anyone who may be directly in front of them. In person contact has dropped as online has risen. For those not online, their available world is shrinking. I don’t know if this is a problem of the modern world, but it is a feature. Just as automobility enabled further suburbanisation and increasing distances between buildings, worsening the environment for those without a car, the always online world increases the effective physical distance between people, reducing the opportunities for those not on-board with the new technology. 

We don’t weep too many tears for those stuck on AOL or Friendster or Orkut or Myspace or Google Plus or the Blogosphere, in a few years this will be Facebook (I hope) and Twitter, and eventually Insta et al., as the Cool Cycle continues its relentless march. The cool kids can’t be caught dead on the same network (wearing the same clothes) with the less cool kids (or their grandparents), and will migrate elsewhere. Being on different networks helps people differentiate their status, but that differentiation is a disconnection, slowing the flow of real ideas and information for the sake of social standing and relative positioning.

Once we have achieved communications saturation, for every increasing network online, producing network externalities for its members, it a world with a fixed time budget, some other physical or virtual social network is shrinking in either membership, attention, or both. Whether we have reached communications saturation is an empirical question, and perhaps brain to brain links will demonstrate how much further we have to go to create a truly social species, but it is feeling pretty saturated to me.

I was interviewed by Michael Condon at ABC Country hour on the Blue Mountains tunnels. A bit of it shows up in the article Blue Mountains tunnel plan …, my quotes are excerpted below:


David Levinson, author and Professor of Transport at the University of Sydney, is not a fan of the project.

He said while it would benefit people who lived in the mountains, as well as tourists and farmers, it would not save much travel time.

“It takes about 13 minutes to drive and if they get that down to seven or eight minutes … that’s an improvement, but it’s not earth-shaking.”

He also wondered about the the likelihood of costs rising, or the project being sold off to private companies.

“Most tunnelled motorways in the Sydney region have been sold off as toll roads … and what happens in 10 years isn’t necessarily what people are projecting today.”

Until there is a publicly-reviewable (and peer-reviewed) business case, it’s inappropriate to spend $10 billion on any infrastructure project. It’s not that I support or don’t support the project, it’s that the proposed tunnel benefits a very specific group of people and is subsidised by everyone, so requires strong evidence that it is worthwhile.

Another issue is that this is a bottleneck during peak times, but if this bottleneck is relieved, the next downstream bottleneck will just be activated. This is hardly the only bottleneck in the Blue Mountains. That argues for tunnelling essentially the entire mountain range (at an enormous amount of money). But peak times are also relatively rare, holiday periods particularly, and perhaps more manageable in a world where more and more people work from home and have flexible schedules.

As my friend and faithful reader Alex W. notes:

The real issue is how to improve the road alignment between Mt Victoria and Hartley.  It is steep and twisty and has ever been thus since the first road was laid out by the colonial Surveyor-General in the 1830s.  Incidentally, the alternative Bells Line of Road between Clarence and Lithgow is scarcely better because of the need to lose 100 metres in altitude in a short distance.

The originally announced tunnel between Mt Victoria and Hartley would probably have solved the combined gradient and curvature problem by building a longer, but underground, route to address the issue that both the road and the railway occupy a narrow ridge from Emu Plains to Mt Victoria.

Somehow, this project has morphed into a mega project with no sense of being staged to deliver early benefits addressing the real problem, not occasional holiday congestion.



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.

  • Karner, Alex, and Dana Rowangould. 2021. “Access to Secure Ballot Drop-off Locations in Texas.” Findings, May.
  • Chauhan, Rishabh Singh, Denise Capasso da Silva, Deborah Salon, Ali Shamshiripour, Ehsan Rahimi, Uttara Sutradhar, Sara Khoeini, Abolfazl (Kouros) Mohammadian, Sybil Derrible, and Ram Pendyala. 2021. “COVID-19 Related Attitudes and Risk Perceptions across Urban, Rural, and Suburban Areas in the United States.” Findings, June.
  • Paez, Antonio, and Christopher D. Higgins. 2021. “The Accessibility Implications of a Pilot COVID-19 Vaccination Program in Hamilton, Ontario.” Findings, May.
  • Allen, Jeff, and Steven Farber. 2021. “Changes in Transit Accessibility to Food Banks in Toronto during COVID-19.” Findings, May.
  • Goodman, Anna, Anthony A. Laverty, Asa Thomas, and Rachel Aldred. 2021. “The Impact of 2020 Low Traffic Neighbourhoods on Fire Service Emergency Response Times, in London, UK.” Findings, May.
  • Goodman, Anna, Anthony A. Laverty, and Rachel Aldred. 2021. “Short-Term Association between the Introduction of 2020 Low Traffic Neighbourhoods and Street Crime, in London, UK.” Findings, May.
  • Cochran, Abigail L., Jueyu Wang, Lauren Prunkl, Lindsay Oluyede, Mary Wolfe, and Noreen McDonald. 2021. “Access to the COVID-19 Vaccine in Centralized and Dispersed Distribution Scenarios.” Findings, May.
  • Jiao, Junfeng, and Amin Azimian. 2021. “Socio-Economic Factors and Telework Status in the US during the COVID-19 Pandemic.” Findings, May.
  • Firth, Caislin L., Michael Branion-Calles, Meghan Winters, and M. Anne Harris. 2021. “Who Bikes? An Assessment of Leisure and Commuting Bicycling from the Canadian Community Health Survey.” Findings, May.
  • Manley, Ed, Stuart Ross, and Mengdie Zhuang. 2021. “Changing Demand for New York Yellow Cabs during the COVID-19 Pandemic.” Findings, May.

Research by Others

Follow-up: Hypothesis of the Month

Corinne Mulley writes: Just a quick note about agglomeration economies.  In an attempt to see how public transport contributed, we surveyed some firms’ employeesabout how often they saw someone on PT that reminded them they should contact them.  It was remarkably frequent.  

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