Of interest, relation of low income neighborhoods and traffic crashes.
Marc Brenman
mbrenman001(a)comcast.net
----- Original Message -----
Traffic injuries much more common in poor areas, study finds
LA Times
http://www.latimes.com/health/boostershots/la-heb-road-crashes-poor-neighbo…
By Karen Kaplan, Los Angeles Times/For the Booster Shots blog
April 19, 2012 , 1:47 p.m.
Here’s another way that rich people are different – they experience far fewer traffic
accidents in their neighborhoods, according to a new study .
This isn’t exactly a shocking conclusion. There are an estimated 40,000 road deaths in the
U.S. each year, and many studies have found that these are more likely to involve
low-income people in low-income areas.
But there’s nothing about being poor that should make a person inherently more vulnerable
to being hurt in a car crash. As researchers from Montreal explained in their study,
“deaths and injuries result from the transfer of a motor vehicle’s kinetic energy at a
rate that exceeds the human body’s protective capacity.”
So what is it about poor neighborhoods that explains the heightened risk? To find out, the
researchers gathered information on all road traffic injuries on the Island of Montreal
between 1999 and 2003. (The island is served by a single ambulance company, which provided
records for the study.) The researchers focused on 19,568 accident victims who got hurt at
17,498 intersections, all of which were located in census tracts with at least some
residents. Intersections that straddled multiple census tracts, were adjacent to highway
on-ramps or were in purely industrial or commercial areas were not included in the
analysis.
Then the researchers took all of those intersections and sorted them into five categories
based on the average household income for the census tract in which they were located. The
main comparisons were between the 20% of intersections in the poorest census tracts and
the 20% of intersections in the wealthiest census tracts. Here’s some of what they found:
* Population density in the poorest census tracts was 2.7 times higher than in the
wealthiest census tracts.
* Average traffic at intersections in the poorest neighborhoods was 2.4 times greater than
in the richest neighborhoods.
* 30% of the intersections in the poorest neighborhoods included a major traffic artery,
compared with only 11.5% of intersections in the richest neighborhoods.
* The number of four-way intersections in the poorest census tracts was nearly twice as
high as in the wealthiest census tracts. Collisions involving injuries are more common at
four-way intersections than at three-way intersections.
The net effect of these (and other) factors was not good for motorists, cyclists or
pedestrians in the lowest-income areas. The researchers found that the number of
pedestrians injured in the poorest census tracts was 6.3 times higher than in the richest
census tracts. People riding in cars were also more vulnerable in the poorest areas – the
number of injured motor vehicle occupants was 4.3 times greater in poor areas than in rich
ones. The story was similar for cyclists – the number of injuries was 3.9 times higher in
poor areas than in rich ones.
The researchers calculated that for every 1,000 additional vehicles that pass through an
intersection each day, the number of people injured in cars rose by 7%, the number of
injured pedestrians rose by 6%, and the number of injured cyclist rose by 5%. Since poorer
neighborhoods had more traffic, they also had more injuries.
“We found that environmental factors associated with a greater risk of crashes” – the
number of people exposed to crashes, the total volume of traffic, and the geometry of
roads and intersections – “were more frequent in the poorest neighborhoods,” the study
authors wrote. These three factors accounted for “a substantial portion” of the difference
between the poorest versus the richest neighborhoods, they added.
“It should be underscored that poverty per se does not produce RTIs [road traffic
injuries] – exposure to moving vehicles does,” they wrote.
The results were published online Thursday by the American Journal of Public Health . The
full study is behind a pay wall, but you can read an abstract here .
Patrick Morency, Lise Gauvin, Céline Plante, Michel Fournier, and Catherine Morency.
(2012). Neighborhood Social Inequalities in Road Traffic Injuries: The Influence of
Traffic Volume and Road Design. American Journal of Public Health. e-View Ahead of Print.
doi: 10.2105/AJPH.2011.300528
Accepted on: Oct 13, 2011 Neighborhood Social Inequalities in Road Traffic Injuries: The
Influence of Traffic Volume and Road Design
Patrick Morency, MD, PhD , Lise Gauvin, PhD , Céline Plante, MSc , Michel Fournier, MA ,
and Catherine Morency, PhD
Patrick Morency, Céline Plante, and Michel Fournier are with the Direction de santé
publique de Montréal, Montréal, Québec, Canada. Patrick Morency and Lise Gauvin are with
the Centre de Recherche du Centre Hospitalier de l'Université de Montréal and the
Département de médecine sociale et préventive de l'Université de Montréal, Montréal,
Québec, Canada. Catherine Morency is with the Département des génies civil, géologique et
des mines, École Polytechnique de Montréal, and the Centre interuniversitaire de recherche
sur les réseaux d'entreprise, la logistique et le transport, Montréal, Québec, Canada.
Correspondence should be sent to Patrick Morency, MD, PhD, Direction de santé publique de
Montréal, 1301 Sherbrooke Est, Montréal (Québec) H2L 1M3, Canada (e-mail:
pmorency(a)santepub-mtl.qc.ca ). Reprints can be ordered at
http://www.ajph.org by clicking
the “Reprints” link.
Contributors
P. Morency conceptualized the study and led the writing. L. Gauvin conceptualized and
supervised the study. C. Plante and M. Fournier contributed to the analyses. C. Morency
assisted with the data collection and analyses. All authors contributed to the writing of
the article.
Objectives. We examined the extent to which differential traffic volume and road geometry
can explain social inequalities in pedestrian, cyclist, and motor vehicle occupant
injuries across wealthy and poor urban areas.
Methods. We performed a multilevel observational study of all road users injured over 5
years (n = 19 568) at intersections (n = 17 498) in a large urban area (Island of
Montreal, Canada). We considered intersection-level (traffic estimates, major roads,
number of legs) and area-level (population density, commuting travel modes, household
income) characteristics in multilevel Poisson regressions that nested intersections in 506
census tracts.
Results. There were significantly more injured pedestrians, cyclists, and motor vehicle
occupants at intersections in the poorest than in the richest areas. Controlling for
traffic volume, intersection geometry, and pedestrian and cyclist volumes greatly
attenuated the event rate ratios between intersections in the poorest and richest areas
for injured pedestrians (−70%), cyclists (−44%), and motor vehicle occupants (−44%).
Conclusions. Roadway environment can explain a substantial portion of the excess rate of
road traffic injuries in the poorest urban areas. (Am J Public Health. Published online
ahead of print April 19, 2012: e1-e8. doi:10.2105/AJPH.2011.300528)
Read More:
http://ajph.aphapublications.org/doi/abs/10.2105/AJPH.2011.300528