Marijuana Impaired Driving Illustrated in Denver Car Crash

car crash

In Denver in July 2014, there was a serious traffic accident caused by a young female driver who was driving impaired. According to her statements to police after the accident, she had drunk one beer and smoked “a bowl” of marijuana before driving.

She was speeding down Colfax Avenue—a 30 mph zone—at 60 miles per hour. When she ran a red light, she crashed into another car and caused six people to be injured. She now has to appear in court to answer to charges of driving impaired and vehicular assault.

The National Highway Transportation Safety Administration (NHTSA) has carefully analyzed the kinds of impairments caused by the use of marijuana. In fact, their website carries the results of their analysis of fifteen different drugs and their impacts on driving performance.

National Highway Transportation Safety Administration notes these effects from using marijuana:

  • Problems with memory and learning
  • Distorted perception
  • Difficulty in thinking and problem-solving
  • Distortion of time and distance
  • Impaired sustained vigilance
  • Loss of coordination in divided attention tasks
  • Difficulty registering, processing and using information
  • Impairment of hand-eye coordination


Specifically, the NHTSA described the effect of marijuana on driver skills this way:

Marijuana has been shown to impair performance on driving simulator tasks and on open and closed driving courses for up to approximately 3 hours. Decreased car handling performance, increased reaction times, impaired time and distance estimation, inability to maintain headway, lateral travel, subjective sleepiness, motor incoordination, and have all been reported. Mixing alcohol and marijuana may dramatically produce effects greater than either drug on its own.

This young woman has tied up her life in legal hassles and expenses, not to mention carrying around the burden of having injured six people. It’s fortunate that no one was killed, which at 60 miles an hour, is a definite possibility.

This is a drug that many people are working very hard to make readily available in every state in our country. It might be good if they read this analysis of effects before going to the polls.


Karen Hadley

For more than a decade, Karen has been researching and writing about drug trafficking, drug abuse, addiction and recovery. She has also studied and written about policy issues related to drug treatment.