James V Ouellet1. 1. Motorcycle Accident Analysis, Playa del Rey, California 90293-8728, USA. hlmtxport@yahoo.com
Abstract
OBJECTIVE: The "risk compensation" hypothesis suggests that individuals offset perceived gains in safety by increasing their risk-taking behavior to maintain a stable or "homeostatic" level of risk. If this is true for motorcyclists, then helmet use, which reduces the risk of brain injury and death, may lead helmet users to take more risks when they ride. Thus, increased risk-taking by helmet users should show up as overrepresentation in crashes, and accident reconstruction should reveal risky behaviors in the seconds just before the crash. This article examines data from two separate studies involving the on-scene, in-depth investigation and reconstruction of motorcycle crashes: 900 in Los Angeles (1976-1977) and another 1082 in Thailand (1999-2000). METHODS: Each crash was investigated on scene within minutes of its occurrence by teams of specially trained researchers and later reconstructed in order to identify precrash and crash events, verify helmet use/nonuse, etc. "Exposure" data on helmet use and other readily visible factors were also collected for the population-at-risk by observing riders who passed by each accident scene some time after a crash that had been investigated by the team. In this article, helmeted and unhelmeted accident-involved riders are compared to each other as well as to the population-at-risk. RESULTS: In Thailand, helmeted riders did not differ significantly from unhelmeted riders in alcohol use, precrash speed, being the primary or sole cause of the crash, or unsafe speed or lane positioning for the traffic conditions; they were no more likely to be in a single-vehicle accident, to crash by running off the road, or to lose control. In Los Angeles, drinking riders were half as likely to wear a helmet as nondrinkers. However, when drinkers and nondrinkers were segregated, helmeted riders were no more likely to cause their crash, run stop signs or red lights, commit other traffic code violations, or run off the road. They did not differ in speed or single-vehicle crash rates. In both studies, helmeted riders were underrepresented in crashes compared to helmet use in the population-at-risk, and helmet use was associated with greater distances traveled. CONCLUSIONS: The data fail to support the hypothesis that the increased safety provided by motorcycle helmet use is offset by more risk-taking while riding. The only evidence of risk compensation was that helmet use increased with greater amounts of travel.
OBJECTIVE: The "risk compensation" hypothesis suggests that individuals offset perceived gains in safety by increasing their risk-taking behavior to maintain a stable or "homeostatic" level of risk. If this is true for motorcyclists, then helmet use, which reduces the risk of brain injury and death, may lead helmet users to take more risks when they ride. Thus, increased risk-taking by helmet users should show up as overrepresentation in crashes, and accident reconstruction should reveal risky behaviors in the seconds just before the crash. This article examines data from two separate studies involving the on-scene, in-depth investigation and reconstruction of motorcycle crashes: 900 in Los Angeles (1976-1977) and another 1082 in Thailand (1999-2000). METHODS: Each crash was investigated on scene within minutes of its occurrence by teams of specially trained researchers and later reconstructed in order to identify precrash and crash events, verify helmet use/nonuse, etc. "Exposure" data on helmet use and other readily visible factors were also collected for the population-at-risk by observing riders who passed by each accident scene some time after a crash that had been investigated by the team. In this article, helmeted and unhelmeted accident-involved riders are compared to each other as well as to the population-at-risk. RESULTS: In Thailand, helmeted riders did not differ significantly from unhelmeted riders in alcohol use, precrash speed, being the primary or sole cause of the crash, or unsafe speed or lane positioning for the traffic conditions; they were no more likely to be in a single-vehicle accident, to crash by running off the road, or to lose control. In Los Angeles, drinking riders were half as likely to wear a helmet as nondrinkers. However, when drinkers and nondrinkers were segregated, helmeted riders were no more likely to cause their crash, run stop signs or red lights, commit other traffic code violations, or run off the road. They did not differ in speed or single-vehicle crash rates. In both studies, helmeted riders were underrepresented in crashes compared to helmet use in the population-at-risk, and helmet use was associated with greater distances traveled. CONCLUSIONS: The data fail to support the hypothesis that the increased safety provided by motorcycle helmet use is offset by more risk-taking while riding. The only evidence of risk compensation was that helmet use increased with greater amounts of travel.
Authors: Yinan Peng; Namita Vaidya; Ramona Finnie; Jeffrey Reynolds; Cristian Dumitru; Gibril Njie; Randy Elder; Rebecca Ivers; Chika Sakashita; Ruth A Shults; David A Sleet; Richard P Compton Journal: Am J Prev Med Date: 2017-06 Impact factor: 5.043
Authors: Jeremy Howard; Austin Huang; Zhiyuan Li; Zeynep Tufekci; Vladimir Zdimal; Helene-Mari van der Westhuizen; Arne von Delft; Amy Price; Lex Fridman; Lei-Han Tang; Viola Tang; Gregory L Watson; Christina E Bax; Reshama Shaikh; Frederik Questier; Danny Hernandez; Larry F Chu; Christina M Ramirez; Anne W Rimoin Journal: Proc Natl Acad Sci U S A Date: 2021-01-26 Impact factor: 12.779