Road Safety Impact of Increased Rural Highway Speed Limits in British Columbia, Canada

Control of vehicle speed is a central tenet of the safe systems approach to road safety. Most research shows that raising speed limits results in more injuries. Advocates of higher speed limits argue that this conclusion is based on older research, that traffic fatalities are decreasing despite higher speed limits, and that modern vehicles are able to safely travel at higher speeds. These arguments were used to justify raising speed limits on rural highways in British Columbia, Canada (July 2014). We used an interrupted time series approach to evaluate the impact of these speed limit increases on fatal crashes, auto-insurance claims, and ambulance dispatches for road trauma. Events were mapped to affected road segments (with increased speed limits) and to nearby road segments (within 5 km of an affected segment). Separate linear regression models were fitted for each outcome and road segment group. Models included gasoline sales to account for changes in vehicle travel. Our main findings were significant increases in (i) total insurance claims (43.0%; 95% Confidence Interval [CI] = 16.0–76.4%), (ii) injury claims (30.0%; 95% CI = 9.5–54.2%), and (iii) fatal crashes (118.0; 95% CI = 10.9–225.1%) on affected road segments. Nearby segments had a 25.7% increase in insurance claims (95% CI = 16.1–36.1%).

[1]  D. Jehle,et al.  Speed kills? Not always: the New York State thruway experience. , 2010, The Journal of trauma.

[2]  S. Garber,et al.  The effects of the new 65 mile-per-hour speed limit on rural highway fatalities: a state-by-state analysis. , 1990, Accident; analysis and prevention.

[3]  Richard A. Retting,et al.  Traffic Speeds Following Repeal of the National Maximum Speed Limit , 1997 .

[4]  Ingrid van Schagen,et al.  Driving speed and the risk of road crashes: a review. , 2006, Accident; analysis and prevention.

[5]  Rune Elvik,et al.  Optimal Speed Limits: Limits of Optimality Models , 2002 .

[6]  Lawrence J Cook,et al.  Effect of repeal of the national maximum speed limit law on occurrence of crashes, injury crashes, and fatal crashes on Utah highways. , 2004, Accident; analysis and prevention.

[7]  Ezra Hauer,et al.  Speed and Safety , 2009 .

[8]  F M Streff,et al.  Effects of the 65 mph speed limit on injury morbidity and mortality. , 1990, Accident; analysis and prevention.

[9]  A. Lund,et al.  THE FATALITY CONSEQUENCES OF THE 65 MPH SPEED LIMITS, 1989 , 1991 .

[10]  J. Herndon,et al.  Effects of the 65-mph speed limit on rural interstate fatalities in New Mexico. , 1989, JAMA.

[11]  Yili Liu,et al.  Queuing Network Modeling of Driver Workload and Performance , 2006, IEEE Transactions on Intelligent Transportation Systems.

[12]  Saeed Maghsoodloo,et al.  THE SAFETY IMPACT OF THE 65 MPH SPEED LIMIT: A CASE STUDY USING ALABAMA ACCIDENT RECORDS. FINAL GRANT REPORT , 1989 .

[13]  David Navon.  The paradox of driving speed: two adverse effects on highway accident rate. , 2003, Accident; analysis and prevention.

[14]  Ian Pike,et al.  Reduction in fatalities, ambulance calls, and hospital admissions for road trauma after implementation of new traffic laws. , 2014, American journal of public health.

[15]  N. Haworth,et al.  VISION ZERO: AN ETHICAL APPROACH TO SAFETY AND MOBILITY , 1999 .

[16]  Rinus Jaarsma,et al.  Making minor rural road networks safer: The effects of 60 km/h-zones. , 2011, Accident; analysis and prevention.

[17]  Göran Nilsson,et al.  Traffic Safety Dimensions and the Power Model to Describe the Effect of Speed on Safety , 2004 .

[18]  Johan Engström,et al.  Effects of visual and cognitive load in real and simulated motorway driving , 2005 .

[19]  U Helfenstein.  When did a reduced speed limit show an effect? Exploratory identification of an intervention time. , 1990, Accident; analysis and prevention.

[20]  Steven T Baldwin,et al.  70-mph speed limit and motor vehicular fatalities on interstate highways. , 2003, The American journal of emergency medicine.

[21]  Elihu D Richter,et al.  Speed, road injury, and public health. , 2006, Annual review of public health.

[22]  P McCarthy.  EFFECT OF SPEED LIMITS ON SPEED DISTRIBUTIONS AND HIGHWAY SAFETY: A SURVEY OF THE LITERATURE. APPENDIX C OF TRB SPECIAL REPORT 254 , 1998 .

[23]  I Johnston.  Reducing injury from speed related road crashes , 2004, Injury Prevention.

[24]  C. Lave.  Speeding, Coordination, and the 55 MPH Limit , 1985 .

[25]  S M Rock,et al.  Impact of the 65 mph speed limit on accidents, deaths, and injuries in Illinois. , 1995, Accident; analysis and prevention.

[26]  Lars Åberg,et al.  Speed choice in relation to speed limit and influences from other drivers , 2000 .

[27]  R Wentz,et al.  Area-wide traffic calming for preventing traffic related injuries. , 2003, The Cochrane database of systematic reviews.

[28]  Jeremy Woolley,et al.  RECENT ADVANTAGES OF LOWER SPEED LIMITS IN AUSTRALIA , 2005 .

[29]  Fotios Petropoulos,et al.  forecast: Forecasting functions for time series and linear models , 2018 .

[30]  A F Williams,et al.  SPEEDS ASSOCIATED WITH 55-MPH AND 65-MPH SPEED LIMITS IN NORTHEASTERN STATES , 1992 .

[31]  B Baruya.  SPEED-ACCIDENT RELATIONSHIPS ON EUROPEAN ROADS , 1998 .

[32]  Paul Barach,et al.  Raised speed limits, speed spillover, case-fatality rates, and road deaths in Israel: a 5-year follow-up. , 2004, American journal of public health.

[33]  Richard Retting,et al.  Traffic speeds associated with implementation of 80 mph speed limits on West Texas rural interstates. , 2008, Journal of safety research.

[34]  Gerald Forbes,et al.  Methods and Practices for Setting Speed Limits: An Informational Report , 2012 .

[35]  D Shinar,et al.  SPEED AND CRASHES: A CONTROVERSIAL TOPIC AND AN ELUSIVE RELATIONSHIP. APPENDIX B OF TRB SPECIAL REPORT 254 , 1998 .

[36]  N. Schuurman,et al.  A population-based analysis of injury-related deaths and access to trauma care in rural-remote Northwest British Columbia. , 2010, The Journal of trauma.

[37]  Paul Barach,et al.  Raised speed limits, case fatality and road deaths: a six year follow-up using ARIMA models , 2007, Injury Prevention.

[38]  Nicholas J Garber,et al.  FACTORS AFFECTING SPEED VARIANCE AND ITS INFLUENCE ON ACCIDENTS , 1989 .

[39]  Peter Cummings,et al.  Freeway speed limits and traffic fatalities in Washington State. , 2002, Accident; analysis and prevention.

[40]  Patrick S. McCarthy.  HIGHWAY SAFETY AND THE 65‐mph SPEED LIMIT , 1991 .

[41]  Elihu D Richter,et al.  Death and injury from motor vehicle crashes: a tale of two countries. , 2005, American journal of preventive medicine.

[42]  Jean-Louis Martin,et al.  A population based estimation of the driver protection provided by passenger cars: France 1996-2005. , 2008, Accident; analysis and prevention.

[43]  Samuel A Labi,et al.  Effects of Geometric Characteristics of Rural Two-Lane Roads on Safety , 2006 .

[44]  David C Grabowski,et al.  Systemwide implications of the repeal of the national maximum speed limit. , 2007, Accident; analysis and prevention.

[45]  R Cuerden,et al.  The relationship between speed and car driver injury severity , 2009 .

[46]  Rune Elvik,et al.  Speed limits, enforcement, and health consequences. , 2012, Annual review of public health.

[47]  Michael Greenstone,et al.  A Reexamination of Resource Allocation Responses to the 65-MPH Speed Limit , 2002 .