Lower volumes, higher speeds: Changes to crash type, timing, and severity on urban roads from COVID-19 stay-at-home policies

New publication: Stiles, J., Kar, A., Lee, J. and Miller, H.J. (2021) “Lower volumes, higher speeds: Changes to crash type, timing, and severity on urban roads from COVID-19 stay-at-home policies,” Transportation Research Record (online first)

Abstract: Stay-at-home policies in response to COVID-19 transformed high-volume arterials and highways into lower-volume roads, and reduced congestion during peak travel times. To learn from the effects of this transformation on traffic safety, an analysis of crash data in Ohio’s Franklin County, U.S., from February to May 2020 is presented, augmented by speed and network data. Crash characteristics such as type and time of day are analyzed during a period of stay-at-home guidelines, and two models are estimated: (i) a multinomial logistic regression that relates daily volume to crash severity; and (ii) a Bayesian hierarchical logistic regression model that relates increases in average road speeds to increased severity and the likelihood of a crash being fatal. The findings confirm that lower volumes are associated with higher severity. The opportunity of the pandemic response is taken to explore the mechanisms of this effect. It is shown that higher speeds were associated with more severe crashes, a lower proportion of crashes were observed during morning peaks, and there was a reduction in types of crashes that occur in congestion. It is also noted that there was an increase in the proportion of crashes related to intoxication and speeding. The importance of the findings lay in the risk to essential workers who were required to use the road system while others could telework from home. Possibilities of similar shocks to travel demand in the future, and that traffic volumes may not recover to previous levels, are discussed, and policies are recommended that could reduce the risk of incapacitating and fatal crashes for continuing road users.

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Movement analytics for sustainable mobility

New paper: Miller, H.J. (2020) “Movement analytics for sustainable mobility.Journal of Spatial Information Science, 20, 115-123.

Invited essay for 10th anniversary issue

Abstract: Mobility is central to urbanity, and urbanity is central to our common future as the world’s population crowds into urban areas. This is creating a global urban mobility crisis due to the unsustainability of our 20th century transportation systems for an urban world. Fortunately, the science and planning of urban mobility is transforming away from infrastructure as the solution towards a sustainable mobility paradigm that manages rather than encourages travel, diminishes mobility and accessibility inequities, and reduces the harms of mobility to people and environments. In this essay, I discuss the contributions over the past decade of movement analytics to sustainable mobility science and planning. I also highlight two major challenges to sustainable mobility that should be addressed over the next decade.

Keywords: movement analytics, mobility science, animal movement ecology, sustainable mobility, urbanity

How to Run a City Like Amazon, and Other Fables

What would it be like to live in a city administered using the business model of Amazon (or Apple, IKEA, Uber,…)?  A new book playfully combines speculative fiction and analysis of 38 different business models when applied to running cities of the future.  How to Run a City Like Amazon, and Other Fables, edited by Mark Graham, Rob Kitchin, Shannon Mattern and Joe Shaw, is available in paperback and PDF from Meatspace Press.

My contribution to the book, Cities Need Mass Transit, shows how a highly personalized transportation system envisioned by Tesla and Elon Musk cannot possibly scale to be an effective urban mobility solution.