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More Californians Drive High Than Drunk – Liability Implications?


Last week, the California Office of Traffic Safety released the results of a recent study showing that a surprisingly high number of weekend drivers have a prescription or illegal drugs in their system. Between the hours of 10 p.m. and 3 a.m. on weekend nights, 14 percent of 1,300 voluntary participants tested positive for various substances. By comparison, only around 7 percent of participants had any alcohol in their system.

One substance dominated the results – 7.4 percent of participants tested positive for marijuana. With more and more states expanding legal access to marijuana, this study points to an increasingly important question. How do we measure marijuana-related impairment and where should we draw the line?

This has important liability implications for impaired-driving car accident victims. While the victims of drunk driving-related crashes have a clear argument that the drunk driver was at fault, how can we tell whether a driver who tests positive for marijuana consumption was actually impaired?

Some studies consistently agree that driving within three hours of marijuana consumption can approximately double the chances of a fatal wreck. Pot is associated with slower response times, hallucinogenic experiences, and memory problems. All of these point to the conclusion that a driver who chooses to drive while high is just as liable as a drunk driver.

That conclusion turns the problem into one of enforcement. Authorities will have to determine a standard for deciding when a driver is impaired enough to be a problem. This may pose special difficulties in the case of marijuana – it is hard to connect THC in the bloodstream to any particular high. THC can linger as long as a week after a high fades away.

Of course, current laws prohibit driving while impaired and this can provide a guideline in some civil cases. It is not yet clear whether or how states like California will develop new rules but this study points to the importance of determining more precise and scientific impairment standards to promote better safety.

Source: Los Angeles Times, “More Californians driving high than drunk on weekends, study says,” Nov. 19, 2012; TIME, “7% of California Drivers Test Positive for Marijuana, but Are They Impaired?” Maia Szalavitz, Nov. 20, 2012