From the American Journal of Public Health, “Reduction in Fatalities, Ambulance Calls, and Hospital Admissions for Road Trauma After Implementation of New Traffic 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.
There are dangerous drivers. Some provinces in Canada passed laws to target them. Then they compared what happened there to provinces that did not, plus Washington State (which, of course, didn’t either). What did they find?
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.
Fatal crashes decreased. Hospital admissions decreased. Even ambulance calls decreased. Because the number of alcohol-related crashed pretty much halved, they’re pretty confident that the improvements they saw were becaused of reduced levels of drinking and driving.
Did you know that the US has pretty much the most relaxed regulations of drinking and alcohol in the world? Sigh.