RESEARCH AND PRACTICE
Reduction in Fatalities, Ambulance Calls, and Hospital
Admissions for Road Trauma After Implementation of New
Traffic Laws
Jeffrey R. Brubacher, MD, MSc, Herbert Chan, PhD, Penelope Brasher, PhD, Shannon Erdelyi, BSc, Edi Desapriya, PhD, Mark Asbridge, PhD,
Roy Purssell, MD, Scott Macdonald, PhD, Nadine Schuurman, PhD, and Ian Pike, PhD
Motor vehicle crashes (MVCs) are a major
public health problem that disproportionately
affects youths and young adults.1 Worldwide,
more than 3300 people per day are killed in
road trauma,2 and many more are disabled.
Crashes are caused by numerous factors, including faulty vehicles and poor road design,
but the majority are attributed to driver-related
factors, especially alcohol-impaired driving,3,4
speeding,5,6 and driver distraction.7,8 In Canada,
driving with a blood alcohol concentration
(BAC) of 0.08% or more is a federal criminal
offense. Most provinces have regulations that
allow for administrative sanctions (fines or
license suspension) for drivers with a BAC of
0.05% or more. Speed limits are set by the
provinces and enforced through administrative
sanctions.
Before September 2010, drunk drivers in
British Columbia were subject to fines and
administrative driving prohibitions of 24 hours
for a BAC of 0.05% or more and of 90 days for
a BAC of 0.08% or more or failure to provide
a breath sample. The 90-day driving ban came
into effect after a 21-day period that allowed
the driver to find alternative means of transportation or to appeal the decision. There were
no vehicle impoundments for drunk drivers. In
addition to administrative penalties, drivers
with a BAC of 0.08% or more and those who
refused to provide a breath sample were subject to possible penalties under the Criminal
Code of Canada. Before September 2010, the
penalty for street racing was vehicle impoundment for 2 days for a 1st offense and for 30
days for 2nd and subsequent offenses in addition to fines and possible criminal code charges.
In September 2010, British Columbia introduced harsher penalties for drunk drivers
and for excessive speeding (> 40 km/h over
the speed limit) as well as for drivers caught
street racing or stunt driving. Under these laws,
Objectives. We evaluated the public health benefits of traffic laws targeting
speeding and drunk drivers (British Columbia, Canada, September 2010).
Methods. We studied fatal crashes and ambulance dispatches and hospital
admissions for road trauma, using interrupted time series with multiple nonequivalent comparison series. We determined estimates of effect using linear
regression models incorporating an autoregressive integrated moving average
error term. We used neighboring jurisdictions (Alberta, Saskatchewan, Washington
State) as external controls.
Results. In the 2 years after implementation of the new laws, significant
decreases occurred in fatal crashes (21.0%; 95% confidence interval [CI] = 15.3,
26.4) and in hospital admissions (8.0%; 95% CI = 0.6, 14.9) and ambulance calls
(7.2%; 95% CI = 1.1, 13.0) for road trauma. We found a very large reduction in
alcohol-related fatal crashes (52.0%; 95% CI = 34.5, 69.5), and the benefits of
the new laws are likely primarily the result of a reduction in drinking and
driving.
Conclusions. These findings suggest that laws calling for immediate sanctions
for dangerous drivers can reduce road trauma and should be supported. (Am J
Public Health. 2014;104:e89–e97. doi:10.2105/AJPH.2014.302068)
which add to but do not replace the older laws,
drivers with a BAC of 0.05% or more may
be subject to license suspension of 3, 7, or 30
days; vehicle impoundment of 3, 7, or 30 days
(discretionary with 3- or 7-day license suspensions, mandatory for 30-day license suspensions); and possible referral to remedial programs
(including ignition interlock) for third-time
offenders. Drivers with a BAC of 0.08% or
more are subject to 30-day vehicle impoundment, 90-day license suspension, and possible
referral to remedial programs (including ignition interlock). In addition, drunk drivers are
subject to fees that include towing costs, vehicle
storage costs, and a processing fee to have their
license reinstated. License prohibitions and
vehicle impoundments are issued immediately
at the roadside on the basis of results of
a handheld breathalyzer. The penalties for
excessive speeding, street racing, and stunt
driving include fees and mandatory vehicle
impoundment of 7 to 60 days.9,10 Table 1
summarizes penalties for drinking and driving
October 2014, Vol 104, No. 10 | American Journal of Public Health
and for speeding and related offenses under
the old versus new traffic laws.
British Columbia’s laws were designed to
deter drinking and driving by increasing the
severity, certainty, and speed of punishment for
drunk drivers with a BAC of 0.05% or more.
Deterrence is effective in laws against traffic
violations,11 and increased likelihood of punishment acts as a greater deterrent than increased severity.12,13 The speed with which
a punishment is applied is an additional deterrent.14 For drivers with a BAC of 0.08% or
more, the administrative sanctions under the
new laws are actually less severe than those
associated with a criminal code conviction for
drunk driving. However, the new sanctions are
applied immediately at roadside and are less
subject to legal challenge, making punishment
more swift and certain. Not all drunk drivers
are deterred by threat of punishment,15 but
through vehicle impoundment and license
suspension, British Columbia’s new laws remove more dangerous drivers from the roads
Brubacher et al. | Peer Reviewed | Research and Practice | e89
RESEARCH AND PRACTICE
TABLE 1—Comparison of British Columbia’s Old and New Speeding and Street Racing Laws
Penalties
a
Driving Offense
After September 2010b,c
Before September 2010
BAC level
0.0–0.049
12-h driving prohibition for drivers
0.05–0.079 (1st offense)
24-h driving prohibition
with restricted license
3-d driving prohibition
Possible 3-d vehicle impoundment
Fees (£ $600)
0.05–0.079 (2nd offense within 5 y)
24-h driving prohibition
7-d driving prohibition
Possible 7-d vehicle impoundment
Fees (£ $780)
0.05–0.079 (3rd offense within 5 y)d
24-h driving prohibition
30-d driving prohibition
30-d vehicle impoundment
Fees (£ $1330)
‡ 0.08 or refuses breath testd
90-d driving prohibition beginning 21 d after the offense
(this 21-d period was to allow driver to arrange alternate
transportation or to appeal the decision)
90-d driving prohibition (immediate)
30-d vehicle impoundment
Fees (£ $1450)
Possible Criminal Code of Canada charges
Speeding and stunt driving
Speeding £ 40 km over limit
Fines and demerit points
No change
Speeding > 40 km per hour or stunt drivinge
Fines and demerit points
7-d vehicle impoundment
Speeding > 40 km per hour or stunt drivinge
(second offense within 2 y)
Fines and demerit points
30-d vehicle impoundment
Fees £ $700
Speeding > 40 km per hour or stunt drivinge
Fines and demerit points
60-d vehicle impoundment
Fees £ $210
(first offense)
Fees £ $1200
(third offense within 2 y)
Street racing
1st offense
Fines and demerit points (street racing only)
7-d vehicle impoundment
48-h vehicle impoundment
Fees £ $210
2nd offense within 2 y
Fines and demerit points (street racing only)
30-d vehicle impoundment
3rd and subsequent offense within 2 y
30-d vehicle impoundment
Fines and demerit points (street racing only)
Fees £ $700
60-d vehicle impoundment
30-d vehicle impoundment
Fees $1200
Note. BAC = blood alcohol concentration; IRP = immediate roadside prohibitions.
a
All penalties that existed before September 2010 remain in effect. Starting September 2010, IRPs provided an additional tool for police to use at their discretion.
b
Since September 2010, police usually apply immediate penalties under the new laws. However, they still have the option of using the preexisting laws instead. Therefore, the 3 typical outcomes for
drivers with BAC ‡ 0.05% or who refuse a breath test are as follows: (1) most get an IRP, (2) some get a 24-h (or 12-h) driving prohibition, and (3) some get a 90-d driving prohibition plus criminal
code charges.
c
Note that the penalties for excessive speeding (> 40 km over limit), street racing, and stunt driving are identical under the new laws.
d
Drivers with 3 offenses for BAC = 0.05%–0.079% or 1 offense for BAC > 0.08% may be referred to the responsible driver program, the ignition interlock program, or both.
e
The new laws expanded the vehicle impound program to introduce and define “stunt driving,” something that was not specifically covered under the old laws.
quicker. High-risk drunk drivers can also be
mandated to undergo therapy, install an alcohol interlock device on their vehicle, or both.
These laws were promoted through public
awareness and educational campaigns and received considerable media coverage. Opinion
and roadside surveys in 2012 found that
majority of drivers were aware of the new
measures16 and that public perception of police
commitment to traffic enforcement had increased.17 During the first 12 months, British
Columbia police used the new laws to issue
22 734 roadside license prohibitions for
drinking and driving. At the same time, the
number of criminal code convictions for impaired driving fell from 8221 per year in the
e90 | Research and Practice | Peer Reviewed | Brubacher et al.
5 years preceding the new laws to 1853 in the
subsequent 12 months (Figure 1). The new laws
were associated with change in driver behavior. In the 2012 British Columbia roadside
surveys, 6.5% of evening and nighttime drivers
tested positive for BAC compared with 9.9% in
2010 before the new laws were introduced.16
Telephone surveys found that the percentage
American Journal of Public Health | October 2014, Vol 104, No. 10
RESEARCH AND PRACTICE
of British Columbia drivers reporting driving
while over the legal limit was above the
national average in 2009 and 2010 but fell
below the national average in 2011 and 2012.18
The new laws included harsher penalties for
excessive speeding but, unlike the case with
drinking and driving, the number of sanctions
for speeding or for excessive speeding did not
increase (Figure 1).
We previously reported a reduction in
alcohol-related fatal crashes in the 2 years after
introduction of British Columbia’s new laws.19
In this study, we investigated the effects of the
new laws on total fatal crashes, hospital admissions, and ambulance calls. We drew on
police, ambulance, and hospital data from
British Columbia and on police data from
adjacent jurisdictions in which similar legislative changes were not implemented.
research ethics board. Briefly, we used an
interrupted time-series approach to model the
impact of the new laws on crashes and medical
events. We assessed the intervention effects
using a linear regression model with an autoregressive integrated moving average (ARIMA)
error term.
METHODS
Data Sources
We used deidentified administrative data
and obtained approval from our institutional
a
Charges, No.
Intervention
1500
Criminal code
90-day ADPs
90-day IRPs
3-, 7-, or 30-day IRPs
1000
500
0
2008
2009
2010
2011
Time
Charges, No.
b
Intervention
20 000
15 000
10 000
2008
2009
2010
2011
Time
c
Charges, No.
Intervention
1200
1000
800
600
400
2008
2009
2010
2011
Time
Note. ADPs = administrative driving prohibitions; IRPs = immediate roadside prohibitions. In part (a), an abrupt decrease
occurred in the number of criminal code charges and 90-day ADPs for impaired driving after the introduction of the new laws
accompanied by an even greater increase in the number of IRPs issued under the new laws (note that, under the old laws,
drivers with criminal code charges were typically also given a 90-day driving prohibition). In parts (b) and (c), the new
laws were not associated with a change in the number of charges for speeding or for excessive speeding. However, under the
new laws, excessive speeding resulted in mandatory vehicle impoundment for 7 days.
FIGURE 1—Monthly charges for (a) impaired driving, (b) speeding, and (c) excessive
speeding: British Columbia, September 2007–September 2011.
October 2014, Vol 104, No. 10 | American Journal of Public Health
We analyzed British Columbia data from
MVC fatalities from police reports (2000--2012), hospital admissions (2005---2011), and
ambulance calls (2004---2012). We obtained
MVC fatality data from Alberta, Saskatchewan,
and Washington State police reports (2000--2012). We did not have access to hospitalization or ambulance data from any jurisdiction
other than British Columbia.
Road fatalities. The British Columbia traffic
accident system contains details of all policereported crashes in British Columbia, including
factors that police believe contributed to the
crash (e.g., speeding, impaired driving). The
traffic accident system is reconciled with coroners’ data to ensure that it captures all fatal
crashes (i.e., those who died on a public road
and within 30 days of the crash). Nonfatal
crashes may not be captured because police
attendance at nonfatal crashes is discretionary.
For this reason, we studied only fatal crashes.
Fatal crashes related to alcohol or speeding
were our outcome of interest, and fatal crashes
unrelated to alcohol or speeding served as an
internal control.
Similarly, we obtained monthly counts of total
fatal crashes and of fatal crashes involving
alcohol or speeding from police reports of
neighboring jurisdictions (Alberta, Saskatchewan,
and Washington State). We used the analyses of
these data as an external comparison to account
for regional trends and conditions that might
explain the observed effects of the new laws in
British Columbia.
Hospital admissions and ambulance
dispatches. All hospital admissions in Canada
are recorded in the Discharge Abstract Database,
which includes mechanism of injury but has no
information on factors that caused the crash. In
this study, we used admissions for road trauma as
a measure of hospital utilization by road injury
victims in British Columbia. We defined “road
trauma admissions” as those with International
Classification of Diseases, 10th Revision (ICD-10),20
Brubacher et al. | Peer Reviewed | Research and Practice | e91
RESEARCH AND PRACTICE
external cause of injury codes ranging from
V02.1 (pedestrian injured in collision with 2or 3-wheeled motor vehicle, traffic accident)
through V89.9 (person injured in unspecified
vehicle accident). We also included sequelae of
transport accidents (Y85, Y850, Y959).
We excluded non---traffic accident events
such as boarding or alighting from a vehicle,
events that occurred on industrial premises,
events that did not involve a motorized vehicle,
and events in which the only vehicle involved
was a streetcar, railway vehicle, specialized
agricultural vehicle, airplane, or watercraft. We
included traffic injury involving snowmobiles and
all-terrain vehicles because these vehicles are
subject to traffic laws when driven on a public
road. We used hospital admissions for non-MVC
trauma (i.e., all other injury codes) as controls.
The British Columbia Ambulance Service
provides emergency medical service for the
entire province. Each call for emergency medical assistance is assigned 1 of 32 Advanced
Medical Priority Dispatch System numbers
using standardized questions. Multiple calls for
the same event are combined into a single
dispatch record. We used ambulance dispatches for traffic and transportation incidents
(code 29) as a measure of ambulance service
use by road injury victims. We used ambulance
calls for non-MVC trauma as controls.
Analysis
For each outcome, we aggregated counts by
month and converted them to rates. For
crashes, rates were per 1 000 000 licensed
drivers. Hospital admissions and ambulance
calls included victims of all ages and were
converted to rates per 1 000 000 British
Columbia residents. We adjusted rates to account for the number of days in each month.
We chose the time before intervention a priori to
accommodate data availability and to exceed the
recommended minimum number of observations required for time-series analyses.21
For the purpose of this study, we considered
fatal crashes to be alcohol related if police cited
alcohol involvement, alcohol suspected, or
ability impaired by alcohol as a contributory
factor for any driver of a motorized vehicle
involved in the crash. We deemed crashes to be
speeding related if police cited exceeding the
speed limit, excessive speed, driving too fast for
conditions, or unsafe speed as a contributory
factor for any driver involved in the crash.
Crashes with multiple contributory factors were
included in all relevant analyses. We conducted
subgroup analyses that excluded crashes involving both alcohol and speeding. We excluded cases in which relevant contributory
factors were cited only for pedestrians or pedal
cyclists.
We analyzed event rates using an interrupted time-series approach. We fitted a multivariate linear regression model that included an
indicator variable for the intervention (new
law) effect, an internal control variable, and
a seasonal ARIMA error term to control for
seasonality, autocorrelation, and data instability. Internal controls served as a surrogate for
unmeasured confounders and trends unrelated
to the intervention. Controls were scaled and
centered for model convergence. We originally
included the effects of other events, such as
a court challenge and temporary suspension of
the new laws (November 2011),22 in the regression model. However, these events did not
have a statistically significant effect on crash
rates, and we omitted them from the final
model.
To complement ARIMA analyses, which
estimate permanent changes in mean crash
rate, we performed supplementary analyses
to identify breakpoints (significant changes in
the slope of the crash rate trendline) and to
estimate the year in which any detected
breakpoint occurred. To do this, we fitted
regression models to annual crash rates with
a segmented relationship for the yearly trend.
The number of breakpoints was automatically
selected but constrained to be less than 3.23,24
Data transformations were made to meet the
assumptions of the model. First, we took the
logarithm of crash rates to stabilize the variance
when necessary. Second, we used differencing
to achieve a stationary time series. If necessary,
we calculated the difference from one period to
the next to remove trends over time. We also
used seasonal differencing to eliminate any
strong seasonal patterns.
An iterative procedure was used to identify
the order of the ARIMA error model. We
selected the initial model using a stepwise
algorithm to minimize the corrected Akaike
information criterion. We explored correlation
structures via plots of the autocorrelation and
partial autocorrelation functions. If the model
e92 | Research and Practice | Peer Reviewed | Brubacher et al.
fit was deemed inadequate, we used residual
diagnostics to identify improved error structures. We selected the model with the lowest
Akaike information criterion that also satisfied
residual assumptions. The error model was
not constrained to be the same across jurisdictions or outcomes.
We fitted all models using conditional-sumof-squares to find starting values. Final estimates were obtained by maximum likelihood.
We performed all regression analyses with R
version 3.0.1 (R Foundation for Statistical
Computing, Vienna, Austria). The intervention
effect was treated as abrupt and permanent.
We considered P < .05 to be statistically significant; all tests were 2-sided.
RESULTS
Between January 2000 and December
2012, 4507 fatal crashes occurred in British
Columbia, including 1121 related to alcohol
and 1600 related to speeding (163 to excessive speed). In 589 fatal crashes, both alcohol
and speeding were involved. We found overall
downward trends and seasonal patterns with
peaks during summer months for both alcoholand speeding-related fatal crashes. Figure 2
shows monthly rates of fatal alcohol-related
crashes over the study period.
Table 2 summarizes the changes in occurrence rates for each outcome after the new laws
went into effect. In the 24 months after British
Columbia’s new laws were implemented, statistically significant reductions occurred in total
fatal crashes and in fatal crashes related to
alcohol and to speeding. Segmented regression
analyses detected 1 breakpoint in the annual
trend for alcohol-related fatal crash rates in
2010 (95% confidence interval [CI] = 2009,
2011). Breakpoints for speeding-related and
all-cause fatal crash rates occurred in 2005,
before the new laws.
In subgroup analyses that excluded crashes
involving both alcohol and speeding, we
found a 46.5% reduction (95% CI = 23.1,
70.0) in alcohol-related crashes and a nonstatistically significant reduction of 21.1%
(95% CI = –4.4, 46.7) in speeding-related
crashes. During the same period, we observed a smaller reduction in alcohol-related
fatal crashes in Alberta (32.7%) and much
smaller reductions in Saskatchewan and
American Journal of Public Health | October 2014, Vol 104, No. 10
RESEARCH AND PRACTICE
Intervention
Rate/1 000 000 Licensed Drivers
11
Fatal alcohol
Fatal non−alcohol and non−speeding
10
9
8
7
6
5
4
3
2
1
0
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012
Time
Note. The vertical line indicates the first full month of implementation of the new laws in October 2010 (intervention
effect = –1.41 fatal alcohol crashes/1 000 000 licensed drivers). The dotted curves represent the smoothed annual
average of monthly rates from the fitted model for fatal alcohol crashes (dark curve) and from observed rates for fatal
nonalcohol and nonspeeding crashes (light curve).
FIGURE 2—Monthly alcohol-related fatal crash rate per 1 000 000 licensed drivers in British
Columbia: January 2000–December 2012.
Washington State (1.2% and 9.8%, respectively); the latter 2 were not statistically
significant. Similarly, fatal crashes related to
speeding decreased by 30.6% (95% CI =
17.0, 41.9) in Washington State. We found
a smaller, nonsignificant decrease in fatal
speeding crashes in Alberta (14.4%) and
a trivial, non---statistically significant increase
in Saskatchewan (2.5%).
During the study period, British Columbia
had 3553 hospital admissions and 32 225
ambulance calls for road trauma per year. Monthly
rates of road trauma---related hospital admissions and ambulance calls are illustrated in
Figures 3 and 4. We found an 8.0% (95% CI =
0.6, 14.9) reduction in hospital admissions and
a 7.2% (95% CI = 1.1, 13.0) reduction in
ambulance calls attributable to road trauma.
DISCUSSION
British Columbia’s new traffic laws were
associated with decreases in fatal crashes
(21.0%) and in hospital admissions (8.0%)
and ambulance calls (7.2%) for road trauma,
corresponding to monthly decreases of 2.21
fatal crashes per 1 000 000 drivers and 5.71
hospital admissions and 47.29 ambulance
dispatches per 1 000 000 residents. Our findings of reductions not only in fatal crashes but
also in ambulance calls and hospital admissions
for road trauma strengthen the conclusion that
British Columbia’s laws were effective in reducing road trauma. An alternate explanation
is that these benefits are attributable to factors
other than the new laws. We feel that this is
unlikely for several reasons. First, we used
internal controls to account for trends in
need for trauma care or the number of fatal
crashes. Second, with the exception of fines for
drivers using cell phones (February 2010),
British Columbia did not introduce any other
significant traffic laws or policy changes in
2010 or 2011. The cell phone laws are unlikely to have had a significant impact on
crash fatality rates because an analysis of
distraction-related fatal crashes (not shown)
showed no intervention effect. Furthermore,
only 11 crash fatalities were attributed to use
of electronic equipment between 2004 and
2012. Finally, we looked at crash fatality outcomes in neighboring jurisdictions and, with
October 2014, Vol 104, No. 10 | American Journal of Public Health
the exception of a probable spillover effect in
Alberta, found no evidence of a reduction in
total fatal crashes.
Another possible explanation for our findings is that changes in reporting practice occurred that coincided with implementation of
the new traffic laws. Police reports, in particular, may be affected by changes in reporting
practice because police do not report all
crashes,25,26 and police classification of the
cause of crashes may be somewhat subjective.
However, we found no evidence of a change in
police reporting practice around the time of this
study. Moreover, we studied only fatal crashes,
which police are obligated to investigate and
which are reconciled with coroners’ data to
ensure no cases are missed. In addition, we
found reductions in outcomes reported from 3
independent sources (police, ambulance, and
hospital). Ambulance dispatch reports and
hospital admissions for road trauma capture
all events that are correctly classified, and we
found no evidence of a change in reporting
of these events. In particular, the Advanced
Medical Priority Dispatch System codes used to
classify ambulance dispatches and the ICD-10,
injury codes for hospital admissions had not
changed during the time of the study. Considering all these factors, our findings are highly
unlikely to be explained by changes in reporting practice.
Other researchers have also found that
both criminal and administrative traffic laws
reduce drunk driving fatalities. Asbridge et al.
studied drunk driving fatalities and found an
18% reduction after Canada criminalized driving with a BAC of 0.08% or more in 196627
and a 14.5% reduction after Ontario implemented license suspensions for drivers with
a BAC of 0.08% or more.28 In a study of US
state laws, Wagenaar and Maldonado-Molina29
found that administrative license suspension
reduced alcohol-related fatal crash involvement
by 5%, whereas postconviction policies (e.g.,
mandatory jail time for those convicted of driving
while impaired) had no discernible effects. Similarly, Traynor30 reviewed US traffic laws and
found that states with more restrictive laws
regulating teen driving and driving under the
influence had lower road fatality rates.
The benefits of British Columbia’s new
laws are likely primarily the result of prevention of crashes caused by drinking and driving.
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TABLE 2—Effects of the New British Columbia Legislation
Intervention Effect
Error Model
Estimate (SE)a
P
% Change (95% CI)
Change in Monthly
Rate per 1 000 000
British Columbia
ARIMA (0,0,0)(2,0,0)12
–0.236 (0.036)b
< .001
–21.0 (–26.4, –15.3)
–2.21
Alberta
Saskatchewan
ARIMA (0,0,0)(3,1,1)12
ARIMA (0,0,0)(0,1,1)12
–0.140 (0.035)b
0.087 (0.892)
< .001
.922
–13.1 (–18.9, –6.9)
0.6 (–10.7, 11.8)
–1.55
0.09
Washington State
ARIMA (3,0,0)(1,1,1)12
–0.549 (0.477)
.25
–5.7 (–15.4, 4.0)
–0.55
British Columbia
ARIMA (2,0,0)(0,1,1)12
–1.408 (0.241)
< .001
–52.0 (–69.5, –34.5)
–1.41
Alberta
ARIMA (0,0,0)(0,1,1)12
–0.396 (0.103)b
< .001
–32.7 (–45.0, –17.6)
–1.03
Saskatchewan
ARIMA (0,0,0)(1,1,1)12
–0.069 (0.840)
.935
–1.2 (–29.8, 27.4)
–0.07
Washington State
ARIMA (0,0,3)(0,1,1)12
–0.374 (0.344)
.276
–9.8 (–27.4, 7.8)
–0.37
–46.5 (–70.0, –23.1)
–0.59
–24.3 (–48.7, 0.1)
–0.44
Event
All-cause fatal MVCs
Alcohol-related fatal MVCs
Alcohol-only related fatal MVCs
British Columbia
Normal
–0.594 (0.153)
< .001
Alberta
ARIMA (2,0,0)
–0.436 (0.224)
.051
Saskatchewan
ARIMA (0,0,0)(2,0,2)12
–0.214 (0.571)
.708
–6.4 (–39.9, 27.1)
–0.21
Washington State
ARIMA (0,0,2)(0,1,1)12
–0.139 (0.197)
.48
–7.7 (–29.1, 13.7)
–0.14
British Columbia
ARIMA (0,0,0)(2,0,0)12
–1.264 (0.279)
< .001
–33.3 (–47.7, –18.9)
–1.26
Alberta
ARIMA (0,0,0)(0,0,1)12
–0.156 (0.091)b
.085
–14.4 (–28.4, 2.2)
–0.45
Saskatchewan
Washington State
ARIMA (0,0,6)(0,1,1)12
ARIMA (1,0,0)(1,0,1)12
0.090 (0.511)
–0.365 (0.091)b
.861
< .001
2.5 (–25.1, 30.1)
–30.6 (–41.9, –17.0)
0.09
–1.13
Speeding-related fatal MVCs
Speeding-only-related fatal MVCs
British Columbia
ARIMA (0,0,2)(2,0,0)12
–0.500 (0.308)
.105
Alberta
Normal
–0.006 (0.181)
.972
–21.1 (–46.7, 4.4)
–0.4 (–21.0, 20.3)
–0.01
–0.50
Washington State
Normal
–0.277 (0.115)b
.016
–24.2 (–39.5, –5.0)
–0.41
Road trauma related hospital admissions: British Columbia
ARIMA (2,1,1)(0,1,1)12
–0.083 (0.040)b
.036
–8.0 (–14.9, –0.6)
–5.71
Road trauma related ambulance calls: British Columbia
ARIMA (0,1,1)(3,1,1)12
–0.075 (0.033)b
.022
–7.2 (–13.0, –1.1)
–47.29
Note. ARIMA = autoregressive integrated moving average; CI = confidence interval; MVC = motor vehicle crash.
a
Estimates are expressed in monthly rate per 1 000 000 or, if the data were log-transformed, as log rate per 1 000 000. In all cases, the estimated effect is also expressed as % change and as
change in monthly rate per 1 000 000.
b
Data were log-transformed.
Consistent with this premise, we found
a marked reduction (52.0%) in fatal alcoholrelated crashes. The segmented regression
analysis finding that alcohol-related fatal
crashes began to decline more rapidly in 2010
strengthens the evidence linking the new law to
a reduction in alcohol-related MVC fatalities.
Neither Saskatchewan nor Washington had
declines in fatal alcohol-related crashes.
Alberta, however, had a 32.7% reduction in
fatal alcohol-related crashes that we attribute to
a spillover effect from the changes in British
Columbia. Spillover effects are common in
studies of law and public policy and are closely
related to the degree of population mobility
between jurisdictions.31 At the time British
Columbia’s new laws were put into effect,
Alberta politicians were debating similar
laws.32 In December 2011, in an example of
policy diffusion,33---35 Alberta passed laws with
immediate roadside penalties for drunk
drivers. Alberta’s new laws were put into effect
incrementally between July and September
2012. It is not surprising that British Columbia’s laws received considerable media coverage in Alberta, with headings such as “Alta.
May Stiffen Drinking and Driving Laws”32 and
“B.C. Drunk Driving Law Sobers Alberta.”36
Many Albertans likely changed their drinking
and driving behavior as a result of press
coverage. In addition, several municipalities in
Alberta have programs that encourage citizens
e94 | Research and Practice | Peer Reviewed | Brubacher et al.
to report impaired drivers.37,38 Increased news
coverage of drinking and driving may have
encouraged greater participation in those programs. Furthermore, the adjacent nature of the
2 provinces, and easy migration of workers
between British Columbia and Alberta, suggests that many drivers might have carried
their knowledge of British Columbia laws into
Alberta either from habit or from not knowing
the policy differences between the 2 provinces.
Finally, it is possible that Alberta police informally increased their own enforcement efforts
in response to reports from British Columbia.
British Columbia’s new laws also targeted
speeding, with harsher penalties for excessive
speeding, street racing, and stunt driving. We
American Journal of Public Health | October 2014, Vol 104, No. 10
RESEARCH AND PRACTICE
a
Rate/1 000 000 BC Residents
Intervention
850
800
750
700
650
600
2005
2006
2007
2008
2009
2010
2011
2012
Time
b
Rate/1 000 000 BC Residents
Intervention
90
80
70
60
50
40
30
2005
2006
2007
2008
2009
2010
2011
2012
Time
Note. BC = British Columbia. The vertical line indicates the first full month of implementation of immediate roadside prohibition programs in October 2010 (intervention effect = –5.7 admissions for
road trauma per 1 000 000 BC residents). The dotted curve represents the smoothed annual average of monthly rates from observed rates in part a and from the fitted model in part b.
FIGURE 3—Monthly hospital admissions per 1 000 000 population for (a) all trauma causes except road trauma and (b) road trauma: British
Columbia, January 2004–March 2012.
found a 33.3% reduction in fatal speeding
crashes in British Columbia. In a subgroup
analysis that excluded crashes related to
both alcohol and speeding, the reduction in
fatal speeding-related crashes was smaller
(21%) and was not statistically significant at the
nominal level. However, this analysis was
based on half as many events, resulting in an
imprecise estimate of the effect (i.e., wide confidence intervals), and important reductions in
this subgroup cannot be ruled out. Other researchers found that both higher fines and
visible enforcement reduce the incidence of
speeding39,40 but that increased enforcement is
more effective.41 British Columbia’s new laws
did not include increased speed enforcement
and did not increase sanctions for the majority
of speeding drivers. This limited scope may
explain why British Columbia’s laws had
a smaller effect on speeding fatalities. Neither
Alberta nor Saskatchewan had reductions in
speeding-related fatal crashes. It is interesting
to note that Washington State had a statistically
significant reduction in speeding-related fatal
crashes. Beginning in July 2010, Washington
began to roll out “target zero teams.”42 These
teams use a systems approach including education and increased enforcement to target speeding, impaired driving, and failure to use seatbelts.
The reduction in speeding-related crashes seen in
Washington may be related to this approach.
Strengths and Limitations
We used multiple data sources to examine
the effects of British Columbia’s new laws on
health outcomes and on fatal crashes. Most
October 2014, Vol 104, No. 10 | American Journal of Public Health
evaluations of traffic laws rely exclusively on
police data,43---46 which often have limited
information on injury severity and may not
capture all injury crashes.25,26 To account
for trends and unmeasured confounders,
we used ARIMA models21 and internal controls.
We also compared British Columbia traffic
fatalities with those in adjacent jurisdictions.
Because medical data do not include factors
that caused the crash, we cannot confirm that
the observed reduction in ambulance calls and
hospital admissions for road trauma was attributable to fewer crashes caused by the targeted risk
factors (alcohol, speeding). Finally, deterrencebased laws often have reduced effectiveness over
time. Longer follow-up will be required to
determine whether the beneficial effects of
British Columbia’s new laws are long lasting.
Brubacher et al. | Peer Reviewed | Research and Practice | e95
RESEARCH AND PRACTICE
a
Rate/1 000 000 BC Residents
Intervention
1800
1700
1600
1500
2004
2005
2006
2007
2008
2009
2010
2011
2012
Time
b
Rate/1 000 000 BC Residents
Intervention
900
800
700
600
500
400
2004
2005
2006
2007
2008
2009
2010
2011
2012
Time
Note. BC = British Columbia. The vertical line indicates the first full month of implementation of immediate roadside prohibition programs in October 2010 (intervention effect = –47 calls for road
trauma/1 000 000 BC residents). The dotted curve represents the smoothed annual average of monthly rates from observed rates in part a and from the fitted model in part b.
FIGURE 4—Monthly ambulance calls per 1 000 000 population for (a) all trauma causes except road trauma and (b) road trauma: British
Columbia, January 2004–March 2012.
Conclusions
Traffic laws that introduced immediate
license suspension and vehicle impoundment
for drunk drivers and vehicle impoundment for
excessive speeding, stunt driving, or street
racing were associated with significant reductions in fatal crashes and in hospital admissions
and ambulance dispatches for road trauma.
These findings suggest that laws calling for immediate sanctions for dangerous drivers can reduce road trauma and should be supported. j
About the Authors
Jeffrey R. Brubacher, Herbert Chan, Edi Desapriya, and
Roy Purssell are with the Department of Emergency
Medicine, Faculty of Medicine, University of British
Columbia, Vancouver. Roy Purssell is also with the British
Columbia Centre for Disease Control, Vancouver. Penelope
Brasher is with the Centre for Clinical Epidemiology and
Evaluation, University of British Columbia. Shannon Erdelyi
is with the Department of Statistics, University of British
Columbia. Mark Asbridge is with the Department of Community Health and Epidemiology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia. Scott Macdonald is
with the Centre for Addictions Research of British Columbia,
University of Victoria, British Columbia. Nadine Schuurman
is with the Department of Geography, Faculty of Environmental Studies, Simon Fraser University, Burnaby, British
Columbia. Ian Pike is with the British Columbia Injury
Prevention and Research Unit, Faculty of Medicine, University
of British Columbia.
Correspondence should be sent to Jeffrey R. Brubacher,
Vancouver Coastal Health Research Pavilion, Room 719,
828 West 10th Avenue, Vancouver, BC, Canada V5Z
1M9 (Jbrubacher@shaw.ca). Reprints can be ordered at
http://www.ajph.org by clicking the “Reprints” link.
This article was accepted April 24, 2014.
access and assisted with methodology. P. Brasher oversaw statistical analysis and helped with interpretation of
results. S. Erdelyi performed statistical analysis under
supervision of P. Brasher and prepared figures and
tables. E. Desapriya contributed relevant background
information on the importance of media awareness
campaigns and on driver surveys showing that drivers
are aware of the new laws. M. Asbridge contributed
to the section on policy diffusion and helped with
interpretation of results. R. Purssell provided background information on details of British Columbia’s
new laws. S. Macdonald provided background information on deterrence theory and its application to
traffic laws. N. Schuurman assisted with data access
and mapping. I. Pike assisted with access to hospital
admission data and with interpretation of hospital
admission data. All authors reviewed and contributed
to the final article.
Acknowledgments
Contributors
J. R Brubacher oversaw the project as a whole and was
primary author of the article. H. Chan coordinated data
e96 | Research and Practice | Peer Reviewed | Brubacher et al.
This research was funded by a grant from the Canadian
Institutes of Health Research and the Canadian Institute for
Health Information. J. R. Brubacher is funded through
American Journal of Public Health | October 2014, Vol 104, No. 10
RESEARCH AND PRACTICE
a Scholar Award from the Michael Smith Foundation for
Health Research.
We thank the Insurance Corporation of British
Columbia for providing access to the data from the British
Columbia Traffic Accident System used in this article;
Julie Wei, Randy Slemko, and the British Columbia
Ambulance Service for providing access to the ambulance dispatch data used in this article; and Neil Arason
(British Columbia Office of the Superintendent of Motor
Vehicles) for providing a detailed explanation of British
Columbia’s old and new traffic laws.
general deterrence: theory and evidence. Criminology.
2001;39(4):865---892.
at: http://www.edmontonsun.com/news/alberta/2010/
11/16/16174126.html. Accessed November 23, 2013.
14. Beccaria C. On Crimes and Punishment. New York,
NY: MacMillan; 1963.
33. Grattet R, Jenness V, Curry TR. The homogenization
and differentiation of hate crime law in the United States,
1978 to 1995: innovation and diffusion in the criminalization of bigotry. Am Sociol Rev. 1998;63(2):286---307.
Human Participant Participation
17. Ministry of Justice, Road Safety Unit, Police Services
Division. Public attitude survey 2012: British Columbia.
Available at: http://www.pssg.gov.bc.ca/policeservices/
publications-index. Accessed February 15, 2014.
This study was approved by the University of British
Columbia Clinical Research Ethics Board.
References
1. World Health Organization. Global Status Report on
Road Safety 2013: Supporting a Decade of Action. Geneva,
Switzerland: World Health Organization; 2013. Available
at: http://www.who.int/violence_injury_prevention/
road_safety_status/2013/en/index.html. Accessed
February 15, 2014.
2. World Health Organization. Global Status Report on
Road Safety: Time for Action. Geneva, Switzerland: World
Health Organization; 2009. Available at: http://www.
who.int/violence_injury_prevention/road_safety_status/
2009. Accessed February 15, 2014.
3. Borkenstein RF, Crowther RF, Shumate RP, Ziel
WB, Zylman R. The role of the drinking driver in traffic
accidents (the Grand Rapids Study). Blutalkohol. 1974;
11(suppl):7---13.
4. Blomberg RD, Peck RC, Moskowitz H, Burns M,
Fiorentino D. The Long Beach/Fort Lauderdale relative
risk study. J Safety Res. 2009;40(4):285---292.
5. Blows S, Ameratunga S, Ivers RQ, et al. Risky driving
habits and motor vehicle driver injury. Accid Anal Prev.
2005;37(4):619---624.
6. Grundy C, Steinbach R, Edwards P, Green J,
Armstrong B, Wilkinson P. Effect of 20 mph traffic speed
zones on road injuries in London, 1986-2006: controlled
interrupted time series analysis. BMJ. 2009;339:b4469.
7. Asbridge M, Brubacher J, Chan H. Cell Phone Use
and Traffic Crash Responsibility: A Culpability Analysis
of Motor Vehicle Collisions in British Columbia. Paper
presented at: Canadian Multidisciplinary Road Safety Conference XXI; May 8-- 11, 2011; Halifax, Nova Scotia, Canada.
15. Houston DJ, Richardson LE Jr. Drinking-and-driving
in America: A test of behavioral assumptions underlying
public policy. Polit Res Q. 2004;57(1):53---64.
16. Beirness DJ, Beasley EE. An evaluation of immediate roadside prohibitions for drinking drivers in British
Columbia: findings from roadside surveys. Traffic Inj
Prev. 2014;15(3):228---233.
18. The Road Safety Monitor 2012: Drinking and
driving in Canada by region: trends. Available at:
http://tirf.ca/publications/project_show.php?pid=16.
Accessed February 15, 2014.
19. Macdonald S, Zhao J, Martin G, et al. The impact on
alcohol-related collisions of the partial decriminalization
of impaired driving in British Columbia, Canada. Accid
Anal Prev. 2013;59:200---205.
20. International Classification of Diseases, 10th Revision.
Geneva, Switzerland: World Health Organization; 1992.
21. Box GEP, Jenkins GM. Time-Series Analysis: Forecasting
and Control. 2nd ed. San Francisco, CA: Holden-Day; 1976.
22. Mulgrew I. B.C.’s tough new impaired-driving rules
declared unconstitutional in part, judge rules. Vancouver
Sun. November 30, 2011. Available at: http://www.
vancouversun.com/news/tough+impaired+driving+
rules+declared+unconstitutional+part+judge+rules/
5790600/story.html. Accessed December 3, 2011.
23. Muggeo VMR, Adelfio G. Efficient change point
detection for genomic sequences of continuous measurements. Bioinformatics. 2011;27(2):161---166.
24. Muggeo VM. Estimating regression models with
unknown break-points. Stat Med. 2003;22(19):3055---3071.
25. Amoros E, Martin J-L, Lafont S, Laumon B. Actual
incidences of road casualties, and their injury severity,
modelled from police and hospital data, France. Eur J
Public Health. 2008;18(4):360---365.
26. Amoros E, Martin J-L, Chiron M, Laumon B. Road
crash casualties: characteristics of police injury severity
misclassification. J Trauma. 2007;62(2):482---490.
8. Caird JK, Willness CR, Steel P, Scialfa C. A metaanalysis of the effects of cell phones on driver performance. Accid Anal Prev. 2008;40(4):1282---1293.
27. Asbridge M, Mann RE, Flam-Zalcman R, Stoduto G.
The criminalization of impaired driving in Canada:
assessing the deterrent impact of Canada’s first per se law.
J Stud Alcohol. 2004;65(4):450---459.
9. Office of the Superintendent of Motor Vehicles.
Road safety rules and consequences of unsafe driving.
Available at: http://www.pssg.gov.bc.ca/osmv/roadsafety/index.htm. Accessed November 23, 2011.
28. Asbridge M, Mann RE, Smart RG, et al. The effects
of Ontario’s administrative driver’s licence suspension
law on total driver fatalities: a multiple time series analysis.
Drugs Education Prev Policy. 2009;16(2):140---151.
10. British Columbia Motor Vehicle Act. Available at:
http://www.bclaws.ca/EPLibraries/bclaws_new/document/
ID/freeside/96318_00. Accessed November 23, 2011.
29. Wagenaar AC, Maldonado-Molina MM. Effects of
drivers’ license suspension policies on alcohol-related
crash involvement: long-term follow-up in forty-six states.
Alcohol Clin Exp Res. 2007;31(8):1399---1406.
11. Shepherd JP. Criminal deterrence as a public health
strategy. Lancet. 2001;358(9294):1717---1722.
12. Wright V. Deterrence in criminal justice: evaluating
certainty vs severity of punishment. Available at:
http://www.sentencingproject.org/doc/Deterrence%
20Briefing%20.pdf. Accessed November 11, 2011.
13. Nagin DS, Pogarsky G. Integrating celerity, impulsivity, and extralegal sanction threats into a model of
34. Asbridge M. Public place restrictions on smoking in
Canada: assessing the role of the state, media, science and
public health advocacy. Soc Sci Med. 2004;58(1):13---24.
35. Shipan CR, Volden C. Policy diffusion: seven lessons
for scholars and practitioners. Public Adm Rev. 2012;72
(6):788---796.
36. Platt M. B.C. drunk driving law sobers Alberta.
Toronto Sun. September 22, 2010. Available at:
http://www.torontosun.com/news/canada/2010/09/
23/15447056.html. Accessed November 12, 2013.
37. Edmonton Police Services. Camrose adopts Curb the
Danger. Available at: http://www.edmontonpolice.ca/
News/SuccessStories/CamroseAdoptsCurbTheDanger.
aspx. Accessed November 15, 2013.
38. Drivers RI. Be the difference: community action for
safe roads. Available at: http://bethedifferencealberta.com/
report-impaired-drivers. Accessed November 23, 2013.
39. Jones B, Haas K, Kirk A, Griffith A. Self-reported
effectiveness of double-fine zones as a speed control
measure. Appl Health Econ Health Policy. 2004;3(1):17---28.
40. Vaa T. Increased police enforcement: effects on
speed. Accid Anal Prev. 1997;29(3):373---385.
41. Ryeng EO. The effect of sanctions and police
enforcement on driver’s choice of speed. Accid Anal Prev.
2012;45:446---454.
42. Target Zero—Washington State strategic highway
safety plan 2013. Available at: http://www.targetzero.
com. Accessed February 11, 2014.
43. Wagenaar AC, Maldonado-Molina MM, Erickson DJ,
Ma L, Tobler AL, Komro KA. General deterrence effects
of US statutory DUI fine and jail penalties: long-term
follow-up in 32 states. Accid Anal Prev. 2007;39:982---994.
44. Andreuccetti G, Carvalho HB, Cherpitel CJ, et al.
Reducing the legal blood alcohol concentration limit for
driving in developing countries: a time for change?
Results and implications derived from a time-series
analysis (2001---10) conducted in Brazil. Addiction.
2011;106(12):2124---2131.
45. Blais E, Gagne M-P. The effect on collisions with
injuries of a reduction in traffic citations issued by police
officers. Inj Prev. 2010;16(6):393---397.
46. Friedman LS, Barach P, Richter ED. Raised speed
limits, case fatality and road deaths: a six year follow-up
using ARIMA models. Inj Prev. 2007;13(3):156---161.
30. Traynor TL. The impact of state level behavioral
regulations on traffic fatality rates. J Safety Res. 2009;
40(6):421---426.
31. Baicker K. The spillover effects of state spending.
J Public Econ. 2005;89(2---3):529---544.
32. Landry F. Alta. may stiffen drinking and driving
laws. Edmonton Sun. November 17, 2010. Available
October 2014, Vol 104, No. 10 | American Journal of Public Health
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