Of Interest: More Crashes on Tax Day and The Evolution of Street Networks

Today's First Link:

The LA Times reports on a study where researchers find that U.S. auto accidents increase on April 15, tax day. From the story:

Deaths from traffic accidents rise 6% on tax day, that mid-April paroxysm of collective financial agony, according to a study published in Wednesday's edition of the Journal of the American Medical Assn.

A pair of Canadian researchers tallied up U.S. tax day traffic fatalities for each year between 1980 and 2009, then compared the figures to those from two "control" days, exactly one week before and one week after. On average, they found, there were 226 deaths on tax day — 13 more than on non-tax days.

The rise in e-filing — which would presumably keep procrastinators from speeding recklessly to the nearest post office — doesn't appear to have put a dent in the trend, said Dr. Donald Redelmeier of the University of Toronto's Institute of Health Policy, Management and Evaluation, who led the study.

Perhaps that's because the heightened danger involves more than a deadline dash to a mailbox. Stress is a likely culprit, Redelmeier said: In general, most accidents are the result of human error, not mechanical failure, and stress has been shown to significantly worsen performance behind the wheel.

I haven't read the study, so I can't comment on the methodology, but it's a provocative thought nonetheless.

And The Second:

A new paper examines the growth of street networks. The authors highlight 'densification' and 'exploration' in network growth. Here is a nice article in Scientific American about the work. From SA:

The world's cities are absorbing one millionadditional people every week—and by 2030, they could consume an extra 1.5 million square kilometers of land, or roughly the area of France, Germany and Spain combined. What would be the best ways for those cities to grow? A new study examines how—before urban planners existed—a group of Italian villages evolved into suburbs outside Milan today. Such studies may eventually help planners optimize future developments.

"We know few things about how cities grow naturally," says Emanuele Strano, a doctoral candidate studying urban geography at Switzerland's École Polytechnique Fédérale de Lausanne who authored the study. "Urban planners believe that with regulations we can control the growth of cities. The question is, how can we control a thing if we don't really know how it behaves?"

The new study takes a step toward that essential understanding. Strano and his colleagues—a group of computer scientists, mathematicians, physicists and urban scholars—teamed up to provide the first quantitative analysis of how unplanned street networks evolve over time. Their results were published March 1 in Nature's "Scientific Reports." (Scientific American is part of Nature Publishing Group.)

"Historically, a lot of these analyses have been done using not such a substantial quantitative basis," says Stephen Marshall, an urban theorist at University College London (U.C.L.) who was not part of the study. "In the areas that I'm familiar with, people might produce a map of a city, and compare and contrast two maps on a more qualitative basis." Marshall also says that this work marks the first time anyone has looked at how those properties change over time.

It's very interesting work. If interested in similar research check out David Levinson's Nexus Group. Here is a link to a newly published paper from Levinson and Arthur Huang that examines network connectivity.