The Difficulties of Spotting Stoned Drivers

If you’ve ever driven past a motorist who’s been pulled over under suspicion of drunken driving, you’ll know that police officers normally ask the perpetrator to execute three simple tasks:

  1. Follow a pen with their eyes while the officer movies it back and forth.
  2. Get out of the car and walk nine steps, heel to toe, turn on one foot and go back nine steps.
  3. Balance on one leg for 30 seconds.

While they may not be the world’s most difficult tasks, these field sobriety tests have proven to be quite effective over time, catching roughly 88 percent of drivers who are under the influence of alcohol. But what about other substances? 

According to a 2012 study by the journal Psychopharmacology, standard field sobriety tests fail to identify when a person is under the influence of THC, the active ingredient in marijuana, 70 percent of the time. In fact, studies have shown that sobriety tests are practically useless when it comes to sussing out stoned drivers, especially if they’re accustomed to driving while under the influence.

The Dangers of Driving Your San Francisco Rental Car Stoned

According to new research published by Canadian researchers in BMJ, people who drive within three hours of smoking marijuana are nearly twice the risk of being in a serious accident compared with sober drivers. The risk for minor collisions, however, saw little to no increase. This is because stoned drivers tend to be more aware of their impairment and thus will compensate for their inebriated state by driving more cautiously. That being said, stoned drivers still lack the reflexes needed to respond to unexpected road hazards and accidents, a side effect that can often have fatal repercussions.

Which is Worse: Drunk Driving or Stoned Driving?

While it is clear that marijuana use causes deficits that affect driving ability, the impact is still much lower than the dangers posed by drunk drivers. According to one recent study, young drivers with the legal blood content limit had an almost 20-fld increase in the risk of a fatal accident compared to a similarly aged sober driver. This is because drunken drivers tend to drive faster than normal, overestimating their skills behind the wheel. As mentioned before, stoned drivers tend to slow down.

The deficits of stoned driving become most apparent in San Francisco rental car drivers when a person is forced to deal with something unexpected while also trying to manage multiple tasks at once. For example, lets say that you’re driving your San Francisco rental car home and you have four other friends in the vehicle with you. This isn’t a big deal, until you notice a woman pushing a stroller up ahead in the crosswalk. A stoned driver will be able to gauge the distance and can figure out if they woman and her baby will be out of the way by the time the driver gets to the crosswalk. Until suddenly the baby in the stroller drops a stuffed animal, slowing the mother down. By the time a stoned driver has the chance to process this new information it is often too late.

How Stoned is Too Stoned?

When it comes to drunk driving, every one knows that there is a legal blood alcohol limit by which all San Francisco rental car drivers are expected to abide by. But just how stoned is too stoned when it comes to driving?

It’s a tough question, and one that many officials are struggling to answer. While blood-alcohol content can be reliably tested with a Breathalyzer, THC levels must be measured from blood or urine samples… not an easy task at the side of the road. This is why only six states have set legal limits for THC concentration in the blood. In Colorado and Washington, where recreational use has been legalized, the limit is five nanograms per milliliter of blood. In some European countries, this limit is set at one nanogram per milliliter.

While determining the exact role of marijuana in traffic deaths is complicated, it’s worth noting that proper policies can help to curb the impacts. For examples, researchers have found that states that legalize medical marijuana have fewer fatal car crashes due to drunk driving. That’s right, it appears that drivers in these states are swapping booze for blunts. And, while it’s not advisable to drive under the influence of either, stats show that fewer fatal accidents are occurring because lighting up raises the risk less then draining a pint.

When it comes time to slide behind the wheel of your San Francisco rental car, remember that driving under the influence of any illegal substance, whether it’s drugs or alcohol, should be avoided at all costs. Arrive alive – drive safe and drive sober in your San Francisco rental car.