Transportist: May 2025
Welcome to the latest issue of The Transportist, especially to our new readers. As always you can follow on Mastodon, or RSS. By popular demand, a BlueSky feed is also available.
Conference
Bridging Transport Research - the biggest and best online conference in transport is coming up soon. The BTR paper submission deadline is the 30th of April.
This year, we have the privilege of having Prof David Levinson (University of Sydney) and Prof Yiqiu Tan (Harbin Institute of Technology) as the Keynote speakers in the eastern Track, and Prof Moshe Ben-Akiva (MIT) and Prof Marianne Hatzopoulou (University of Toronto) giving a Keynote speech in the Western Track.
At zero cost, and practically zero carbon, BTR brings transportation engineers, planners, & policymakers together globally by removing the burden of travel, the cost of registration, & emissions associated with transport & accommodations – EVERY YEAR.
The Accessibility Turn
I first encountered the concept of accessibility in a transport planning class during the late 1980s. In Susan Hanson’s (1986) Geography of Urban Transportation was an equation adapted from Walter Hansen’s foundational 1959 article:
Resilience and Adaptability Triangles in Networks
When a network faces disruption, understanding its response is crucial. Resilience, reliability, and robustness describe how networks resist, recover from, and even benefit from shocks. Grounded in systems theory and enriched by research across several fields, resilience theory now plays a critical role in everything from cybersecurity to urban planning.
Media Mentions
SUVs Increase Congestion
Study: More SUVs on Minnesota roads are making traffic worse by Nina Moini and Aleesa Kuznetsov (MPR).
How SUVs Are Making Traffic Worse: As larger, taller sport utility vehicles took over US roads, they also aggravated highway congestion, according to a new study. It’s yet another ill effect of “car bloat.” by
(@BlueSky)
Based on this recent paper:
Gao, Yang and Levinson, David (2025) The rise of trucks and the fall of throughput. Transportmetrica A: Transport Science, 1–28. https://doi.org/10.1080/23249935.2025.2477817 [doi]
Yes, I’ve been in Sydney 8 years, but the Minnesota open data sets made available by MnDOT keep on giving and giving; I wish New South Wales had the same availability.
Ramp Meters
Also there is this:
This is an excellent recent video about a study from 25 years ago.1
That study generated the following papers
Zhang, Lei and David Levinson (2010). Ramp Metering and Freeway Bottleneck Capacity. Transportation Research part A 44(4) 218-235. [doi]
Levinson, David and Lei Zhang (2006) Ramp Meters on Trial: Evidence from the Twin Cities Metering Holiday. Transportation Research part A 40(10) 810-828. [doi]
Zhang, Lei and David Levinson (2005) Balancing Efficiency and Equity of Ramp Meters. ASCE Journal of Transportation Engineering 131(6) 477-481. [doi]
Levinson, David and Lei Zhang (2004) Evaluating Effectiveness of Ramp Meters: Evidence for the Twin Cities Ramp Meter Shut-off. (145-166) in Assessing the Benefits and Costs of Intelligent Transportation Systems (ed. David Gillen and David Levinson) Kluwer Publishers.
Zhang, Lei and David Levinson (2004) Optimal Freeway Ramp Control without Origin-Destination Information. Transportation Research part B 38(10) 869-887. [doi]
Zhang, Lei and David Levinson (2004) Some Properties of Flows at Freeway Bottlenecks. Journal of the Transportation Research Board 1883 122-131. [doi]
Levinson, David and Atif Sheikh (2002) Traffic Equilibration: The Case of the Twin Cities Ramp Meter Shut Off. 580-587 Proceedings of International Conference on Traffic and Transportation Studies held in Guilin, China July 2002, ASCE Washington DC.
Zhang, Lei and David Levinson (2002) Estimation of Demand Response to Ramp Metering. 674-681 Proceedings of International Conference on Traffic and Transportation Studies held in Guilin, China July 2002, ASCE Washington DC.
Links
EVs
Posted without comment. “Hackers turn Silicon Valley crosswalks into mockery of Musk, Zuckerberg”. [they hacked the pedestrian actuator and audio signal system].
Aviation
Money
Safety and Security
Your regular reminder that cars are weapons:
Man drives into protestors outside a Tesla dealership [Palm Beach Florida] (nobody hurt sheriff says).
Pickup truck strikes 2 protesters at [Watertown] Massachusetts Tesla dealership, police say
Potholes for traffic calming (for real)
Survey: Americans Still Want Police To Cut Traffic Stops That Don’t Make Anyone Safer
Transit
Only a minor quibble, they demoted me from 25 years ago, I was actually a young Assistant Professor at Minnesota at the time, not a grad student.
