Effectiveness of a Safe Routes to School Program in Preventing School-Aged Pedestrian Injury

Article (PDF Available)inPEDIATRICS 131(2) · January 2013with28 Reads
DOI: 10.1542/peds.2012-2182 · Source: PubMed
Abstract
Background: In 2005, the US Congress allocated $612 million for a national Safe Routes to School (SRTS) program to encourage walking and bicycling to schools. We analyzed motor vehicle crash data to assess the effectiveness of SRTS interventions in reducing school-aged pedestrian injury in New York City. Methods: Using geocoded motor vehicle crash data for 168 806 pedestrian injuries in New York City between 2001 and 2010, annual pedestrian injury rates per 10 000 population were calculated for different age groups and for census tracts with and without SRTS interventions during school-travel hours (defined as 7 am to 9 am and 2 pm to 4 pm, Monday through Friday during September through June). Results: During the study period, the annual rate of pedestrian injury decreased 33% (95% confidence interval [CI]: 30 to 36) among school-aged children (5- to 19-year-olds) and 14% (95% CI: 12 to 16) in other age groups. The annual rate of school-aged pedestrian injury during school-travel hours decreased 44% (95% CI: 17 to 65) from 8.0 injuries per 10 000 population in the preintervention period (2001-2008) to 4.4 injuries per 10 000 population in the postintervention period (2009-2010) in census tracts with SRTS interventions. The rate remained virtually unchanged in census tracts without SRTS interventions (0% [95% CI: -8 to 8]). Conclusions: Implementation of the SRTS program in New York City has contributed to a marked reduction in pedestrian injury in school-aged children.

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DOI: 10.1542/peds.2012-2182
; originally published online January 14, 2013; 2013;131;290Pediatrics
Charles DiMaggio and Guohua Li
Pedestrian Injury
Effectiveness of a Safe Routes to School Program in Preventing School-Aged
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Effectiveness of a Safe Routes to School Program in
Preventing School-Aged Pedestrian Injury
WHATS KNOWN ON THIS SUB JECT: A number of studies have
demonstrated community acceptance of Safe Routes to School
interventions as well as their success in addressing perceptions
about safety, but little is known about their effectiveness in
reducing pedestrian injury risk in school-aged children.
WHAT THIS STUDY ADDS: Implementation of a Safe Routes to
School program in New York City may have contributed to
a substantial reduction in school-aged pedestrian injury rates,
with the effects largely limi ted to school-travel hours in census
tracts with these intervent ions.
abstract
BACKGROUND: In 2005, the US Congress allocated $612 million for a
national Safe Routes to School (SRTS) program to encourage walking
and bicycling to schools. We analyzed motor vehicle crash data to as-
sess the effectiveness of SRTS interventions in reducing school-aged
pedestrian injury in New York City.
METHODS: Using geocoded motor vehicle crash data for 168 806
pedestrian injuries in New York City between 2001 and 2010, annual
pedestrian injury rates per 10 000 population were calculated for
different age groups and for census tracts with and without SRTS
interventions during school-travel hours (dened as 7
AM to 9 AM and 2
PM to 4 PM, Monday through Friday during September through June).
RESULTS: During the study period, the annual rate of pedestrian injury
decreased 33% (95% condence interval [CI]: 30 to 36) among school-
aged children (5- to 19-year-olds) and 14% (95% CI: 12 to 16) in other
age groups. The annual rate of school-aged pedestrian injury during
school-travel hours decreased 44% (95% CI: 17 to 65) from 8.0 injuries
per 10 000 population in the preintervention period (20012008) to 4.4
injuries per 10 000 population in the postintervention period (2009
2010) in census tracts with SRTS interventions. The rate remained
virtually unchanged in census tracts without SRTS interventions (0%
[95% CI: 8 to 8]).
CONCLUSIONS: Implementation of the SRTS program in New York City
has contributed to a marked reduction in pedestrian injury in school-
aged children. Pediatrics 2013;131:290296
AUTHORS: Charles DiMaggio, PhD, MPH,
a
,
b
,
c
and
Guohua Li, MD, DrPH
a
,
b
,
c
a
Department of Anesthesiology, Columbia University College of
Physicians and Surgeons, New York, New York;
b
Department of
Epidemiology, Mailman School of Public Health, New York, New
York; and
c
Center for Injury Epidemiology and Prevention,
Columbia University Medical Center, New York, New York
KEY WORDS
environment and public health, injuries, motor vehicles,
prevention and control
ABBREVIATIONS
CIcondence interval
DOTDepartment of Transportation
SRTSSafe Routes to School
Dr DiMaggio conceived the study, acquired and had access to
the data, obtained institutional review board approval,
conducted all analyses, wrote the initial manuscript, interpreted
the results, and had nal approval of the version to be
published; and Dr Li contributed to the study design, statistical
analysis, interpretation of the results, drafting of the
manuscript, and critical revision of the manuscript for
important intellectual content.
www.pediatrics.org/cgi/doi/10.1542/peds.2012-2182
doi:10.1542/peds.2012-2182
Accepted for publication Oct 16, 2012
Address correspondence to Charles DiMaggio, PhD, MPH,
Columbia University Medical Center, Department of
Anesthesiology, 622 West 168 St, Room PH5-531, New York, NY
10032. E-mail: cjd11@columbia.edu
PEDIATRICS (ISSN Numbers: Print, 0031-4005; Online, 1098-4275).
Copyright © 2013 by the American Academy of Pediatrics
FINANCIAL DISCLOSURE: The authors have indicated they have
no nancial relationships relevant to this article to disclose.
FUNDING: This research was supported by grants 1 R21
CE001816 and 1 R49 CE002096 from the National Center for
Injury Prevention and Control of the Centers for Disease Control
and Prevention, and grant DA029670 from the National Institute
on Drug Abuse. Funded by the National Institutes of Health (NIH).
290 DIMAGGIO and LI
at Columbia University on February 14, 2013pediatrics.aappublications.orgDownloaded from
Children are known to be at heightened
risk for pedestrian injury.
1
In 2006,
20% to 25% of all children aged ,19
years who were killed in motor vehicle
crashes were pedestrians, and pedes-
trian injuries were the most common
cause of traumatic brain injury for
5- to 9-year-olds.
2
Pedestrian injury
accounts for 31% to 61% of all injury-
related hospital admissions (nearly
18 000 each year) in children and
requires surgical intervention in 11%
of those cases.
3
The consequences of pediatric pedes-
trian crashes extend beyond that of the
immediate injury. Twenty-three percent
of all children struck by cars can be
expected to experience some psycho-
logical sequelae,
4
and their parents are
at increased risk for psychological
symptoms.
5
At the societal level, con-
cern about pediatric pedestrian injury
has been linked to declines in chil-
drens activity and may contribute to
childhood obesity.
6,7
In 2005, to help address the health and
societal consequences of the decline
in walking and bicycling to school, the
US Congress created the federal
Safe Routes to School (SRTS) program
as part o f the federal Safe, Account-
able, Flexible, Efcient Transportation
Equity Act. The program allocated
$612 million for scal years 2005 to
2009 for state depar t ments of trans-
por t ation to build sidewalks, bicycle
lanes, and safe crossings, to improve
signage, and make other improve-
ments to the built environment to
allow children to more safely travel to
school.
8
As of 2010, departments of
transportation in all 50 states had
introduced safety improvements at
10 400 of the nations 98 706 elemen-
tary and secondary schools. Interven-
tions consist primarily of sidewalk
improvements (19%), trafccalming
(14%), pedestrian/bicycle access
(14%), and education (14%) . The dis-
tribution of projects mirrored the
population density of school-aged
children across the United States.
9
New York State received $31 million
dollars fromthe2005Safe,Accountable,
Flexible, Efcient Transportation Equity
Act SRTS federal budget allocation. As
part of this funding, the New York City
Department of Transportation (DOT)
introduced safety improvements at 124
schools with the highest injury rates.
The work included new trafc and pe-
destrian signals; the addition of exclu-
sive pedestrian crossing times, speed
bumps, speed boards (radar-equipped
digital signs that tell drivers how fast
they are moving), and high-visibility
crosswalks; and new parking regu-
lations. As of 2009, the New York City
DOT reported that 100% of the short-
term safety improvements...are com-
plete and that additional longer-term
capital improvements had advanced
far enough for the DOT to propose
expanding the program to an addi-
tional group of 100 schools.
10
Although a number of studies have as-
sessed programmatic aspects of SRTS
programs and evaluated their effect on
childrens physical activity,
1113
little is
known about the effectiveness of the
SRTS program in reducing pedestrian
injury risk in school-aged children. We
assessed whether the implementation
of an SRTS program in New York City
was associated with a decrease in
school-aged pedestrian injury.
METHODS
Data and Variables
Motor vehicle crash data were obtained
from the New York City DOT Ofce of
Research, Implementation, and Safety.
The data were based on police inves-
tigations forall crashes in New York City
involving death, personal injury, or
property damage to any 1 person in
excess of $1000 for the years 2001 to
2010. The data are entered by an in-
vestigating law enforcement ofcer
onto a form (MV-104AN) and abstracted
into a Microsoft Access database by
personnel of the New York City DOT.
Among the many variables are date of
the crash, age, and gender of injured
individuals, extent of injury (coded as
possible,”“non-incapacitating,”“inca-
pacitating, or killed), contributing
factors, and Global Positioning System
based latitude and longitude of the
crash location.
The crash data were in a relational set
of Microsoft Access les linked by a
unique crash identication number.
SQL syntax was used to translate the
related les into a single at text le
with 1 observation for each pedestrian
crash. Crashes involving pedestrians
were identied by using an indicator
variable for pedestrians (Body Type =
35) or bicyclists (Body Type = 36)
and were cross-validated against a
variable in a separate linked table that
similarly identied pedestrians (Ve-
hicle Type = 6). The data were read
into the R statistical analysis pro-
gram
14
and evaluated for outliers, in-
consistent values, and missing entries.
Dateand time variablesweretranslated
into POSIX objects to extract time vari-
ables for year, month, day, and hour. A
school-travel time indicator variable
was created to identify crashes that
occurred during days and hours when
school-aged children would be expec-
ted to be traveling to or from school.
We dened this time period as 7
AM to
9
AM or 2 PM to 4 PM, Monday through
Friday between September and June.
A geographic variable was created by
using crash latitude and longitude
coordinates, and crashes were as-
signed to census tracts by using the
R maptools package.
15
SRTS data were similarly obtained from
the New York City DOT and consisted of
ArcGIS shapeles for 124 New York City
schools selected by the DOT for SRTS
interventions. These schools were se-
lected from the citys 1471 schools
ARTICLE
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because they had the highest rates of
pedestrian injury. As of January 2009,
twelve schools had completed shor t-
term intervention measures such as
new crosswalk markings and had
replaced or improved signage and
completed capital construction proj-
ects. Eighteen schools had completed
short-term interventions and had cap-
ital construction underway. Ninety-four
schools had either started or planned
to start interventions but had not yet
begun capital construction projects at
the time the study was conducted.
We extracted dBase (.dbf) les from the
ArcGIS shapeles that contained the
SRTS school intervention information
and read them into the R statistical
analysis program. We combined the
12 schools that had completed both
short-term measures and capital con-
struction by 2009 and the 18 schools
that had completed short-term inter-
ventions and had capital construction
projects ongoing by 2009 into a group
of 30 schools located within 30 in-
tervention census tracts. The compar-
ison nonintervention census tracts
were dened as those containing
schools that were not included as 1 of
the 124 SRTS schools. Because there
was insufcient information to accu-
rately classify them as SRTS in-
tervention sites, we excluded the 94
census tracts that contained schools
that may or may not have started
short-term interventions and had not
yet started capital construction proj-
ects at the time the study was con-
ducted. To account for changes in
census tracts between 2000 and 2010,
we conrmed that all census tracts
which contained intervention sites
were present in both the 2000 and 2010
data les.
Population data were based on age-
stratied US Census les from both
the 2000 and 2010 decennial census at
the tract level.
16
School-aged children
were dened as those aged 5 to 19
years. This denition was intended to
capture data on children who could be
enrolled in an intervention or non-
intervention New York City school. We
dened 4 comparison age groups
who would not be enrolled in an in-
tervention or nonintervention school:
children aged ,5 years, young adults
aged 20 to 29 years, adults aged 30 to
64 years, and the elderly aged $65
years. Populations at the census tract
level were extrapolated over time by
using linear interpolation and com-
bined for age groups and intervention
versus nonintervention census tracts
to make comparisons.
The preintervention period was dened
as the 8 years from 2001 to 2008, and
the intervention period as the 2 years
from 2009 to 2010. We based this de-
nition on a conservative estimate that
by 2009, the intervention school sites
had completed all short-termmeasures
and had either completed or nearly
completed capital construction.
Analysis
Rates per 10 000 population for pe-
destrian injuries were calculated and
percent changes in pedestrian injury
rates during school-travel hours were
compared among different age groups
and between census tracts with and
without SRTS interventions. This cal-
culation was exclusive of the 94 census
tracts where short-term intermediate
SRTS interventions or planned capital
constructions had not been completed
by 2010.
We calculated rate differences and
proportion changes with 95% con-
dence intervals (CIs) by using the
epitools package in the R statistical
analysis program.
17
Graphical results
FIGURE 1
Pedestrian crashes per 10 000 population according to age group, New York City, 2001 2010.
292 DIMAGGIO and LI
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were plotted with smoothed loess
curves and 95% condence bands by
using the R ggplot2 package.
18
The study protocol was approved by
the Columbia University Medical Center
institutional review board.
RESULTS
The data consisted of 168 806 pedes-
trian crashes from 2001 through 2010.
During the study period, the total an-
nual number of pedestrian crashes for
all age groups decreased 14.4% from
18 961 in 2001 to 16 226 in 2010. When
stratied according to age group, the
most pronounced reduction in the
count of pedestrian crashes was in
school-aged children, which declined
38.2% from 5822 injuries in 2001 to
3597 injuries in 2010.
During the study period, annual pe-
destrian injury rates decreased 33%
(40.9 injuries per 10 000 in 2001 to 27.4
per 10 000 in 2010) in school-aged
children but remained fairly stable in
other age groups (Fig 1, Table 1).
Among school-aged children, the 5- to
9-year-old group experienced the larg-
est decline in pedestrian injury rates
(42% [95% CI: 3746]) followed by the
10- to 14-year-olds (35% [95% CI: 31
39]) and the 15- to 19-year-olds (18%
[95% CI: 1124]), respectively (Fig 2).
During the 10-year study period, a total
of 4760 school-aged pedestrian injuries
occurred during school-travel hours.
The rate of school-aged pedestrian in-
jury during school-travel hours in 2001
was 4.4 injuries per 10 000 population,
which decreased to 3.8 injuries per
10 000 population in 2010 (P = .01). The
proportion of school-aged pedestrian
injuries in census tracts with SRTS
interventions that occurred from 7
AM
to 9 AM decreased from 8.2% of all
school-aged pedestrian injuries in
2001 to 5.7% in 2010. In census tracts
without SRTS interventions, the pro-
portion of school-aged pedestrian
injuries that occurred from 7
AM to 9 AM
increased from 6.6% of all school-aged
pedestrian injuries in 2001 to 7.9% in
2010.
There was a 44% (95% CI: 0.170.65)
reduction in school-aged pedestrian
injury rates between preintervention
and postintervention periods in cen-
sus tracts with SRTS interventions sites
compared with no change in census
tracts without SRTS interventions (0%
[95% CI: 0.08 to 0.08]). The rate of
school-aged pedestrian injury during
school-travel hours in census tracts
with SRTS interventions was nearly
halved, from 8.0 per 10 000 population
per year during 20012008 to 4.4 per
10 000 population per year during
20092010; the rate in census tracts
without SRTS interventions remained
at 3.1 pedestrian injuries per 10 000
population per year in both time peri-
ods (Fig 3).