The legalization of marijuana in the United States seems to have picked up speed in recent years. It’s now legal in eight states and the District of Columbia. More states have referendums around legalizing marijuana on the ballot in upcoming statewide elections.

Arrests of drivers with marijuana in their system increased from 8.6 to 12.6 percent between 2007 to 2014, according to a report done by the National Highway Traffic Safety Administration (NHTSA). The percentage of night drivers in the state of Washington who tested positive for marijuana increased from 7.8 to 18.9 percent one year after the state made it legal.

What does it all mean? How safe are people on the road with drivers under the effects of marijuana? And how is the commercial driving industry impacted by the new laws?

Limited law enforcement resources

Drugs were a factor in 43% of fatal crashes in 2016. Most equipment provided to law enforcement lacks the ability to single out cannabis as the primary influence on a person’s driving. Standard field sobriety tests often aren’t enough to flush out drivers who may be under the influence of marijuana.

Urine tests done hours later can’t always show how much of the drug was in the driver’s system at the time of an incident. Even tests designed to find THC can’t confirm the degree of marijuana influence on a driver at the time.

Most DUI’s issued offer no distinction between the offender being influenced by alcohol, marijuana, or any other drug. The city of Yakima in Washington recorded 296 DUI arrests in 2012. That number increased to 331 in 2016, with 79 of those crashes ending in fatalities. That’s double the number recorded in 2012.

Marijuana’s effect on drivers

Studies done on the effects of cannabis on drivers demonstrated increased reaction times and lane weaving. An evaluation of nine previous studies done marijuana’s effect on drivers showed that the risk of a crash rose anywhere from 10 percent all the way up to 61 percent.

One of the dangers of marijuana use is the unpredictability of the effects on different drivers. Some may smoke it and feel few of the effects. Others might imbibe edibles earlier in the day and be heavily under the influenced by the time they get inside of a car.

Marijuana slows reaction times, meaning that drivers under its influence may not slow down or stop at the sudden appearance of an obstacle. That increases the danger for others on the roads with them.

The impact of legal marijuana on commercial driving

Questions remain for CDL drivers tasked with transporting goods throughout the country. The classification of the drug as a Schedule I narcotic hasn’t changed. That means entities like truck driving schools and commercial driving companies must grapple with questions about drug testing and even transporting marijuana to places where the drug is legal. States like Florida struggle to handle issues like whether drivers should be able to have a medical marijuana card.

Drivers choosing to consume any type of cannabis in states where its legal put both their jobs and the safety of others on the line. These drivers often drive large rigs pulling heavy loads, sometimes with hazardous materials. One slip in concentration could cost many people their lives.

The DOT and marijuana regulation

The Department of Transportation maintains a zero-tolerance policy with regards to commercial drivers using marijuana. They recommend that any driver caught with the drug in their system be immediately removed from their job. They must work with a Substance Abuse Professional and complete what’s called the Return to Duty Process.

The increased need for vigilance in the face of strict DOT drug testing regulations means that the trucking industry must bear the cost of marijuana legalization. They can’t afford to have impaired drivers on the road putting the livelihood of their companies at risk.

The need for better law enforcement tools and screening methods for cannabis intoxication only grows as more states look into legalizing the drug. It’s more vital than ever that the public has the full facts at their disposal about the risks posed by driving under the influence of marijuana.