Narrow lanes are safer than wide ones
A little over a month ago, Johns Hopkins University released the largest-ever research on travel lane width and safety, providing conclusive evidence that 9- and 10-foot lanes do not contribute to greater automobile crashes and, in some cases, reduce collisions. Traffic engineers have long shunned narrower lanes—which benefit walkable cities by providing more room for pedestrians, bicyclists, and landscaping—citing safety concerns.
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"Can road capacity expansions provide a solution to traffic?" (Hint: data says no)
From the paper's abstract:
Building more roads is a commonly employed policy intervention to reduce congestion. This strategy, however, is controversial because under certain conditions road capacity expansions may induce growth in traffic volumes. A crucial precursor to understanding whether road capacity expansions provide a solution to congestion is to quantify the technology driving congestion in urban road networks. This congestion technology describes the variation in performance of the network, often represented by traffic flow through the road network, over its intensity of use given by the number of vehicles in the network.
A blog post on the State Smart Transportation Initiative looks at the study and shares a quote on the findings:
Our results suggest that capacity expansions do not lead to substantial changes in the average travel speed in the network. Thus, building more roads in major urban areas may create more congestion, pollution and collisions. Moreover, such policies may also increase the other wider negative consequences of vehicular travel such as global warming and climate change as they allow more mobility for urban residents.
And then they finish with their own thoughts:
They note that some targeted capacity expansions are inevitable, but other congestion management strategies like operational improvements, congestion pricing, and parking management could be more beneficial.
Finally, they add that while roadways become less efficient as the density of users increases, literature overwhelmingly suggests the opposite is true for rail and bus networks. "Thus," explain the authors, "public transport services are potentially more productive and cost-efficient compared to vehicular travel in dense city centres."
This study, while novel in its approach, only adds to the evidence and general understanding of induced demand, which more transportation agencies are recently coming to terms with.
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"How to Quit Cars"
The article is a high level review and summary of two books: Carmageddon by Daniel Knowles and Henry Grabar’s Paved Paradise.
Carmageddon by
Paved Paradise by
I strongly agree with the thrust of this article. Ending cars and changing the perspective from necessity to outright evil. Sadly, as the article explains, it is not an easily solved thing - especially in America.
My work is about to change offices. Out of curiousity I looked up the comparative commute times for me. If I drive my own car. I can make it in 20-30 minutes. Using public transit I'm looking at 75-90 minutes. Now, there is some attraction to this in that I am not paying for gas. The responsibility of driving is gone. I could even sit and work on the laptop or something possibly. But that difference in time is dramatic. If I could make the trip in 45-60 minutes I very much would make this change. But that length of commute increase is tough as it would require me to be away from home for an hour more each day.
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