NEWPORT BEACH ( — A new study links recreational marijuana use to an alarming increase in fatal traffic crashes in states that have legalized pot.

And Southern California law enforcement agencies are worried about the same trend here if legalized marijuana makes it onto the ballot in November.

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The AAA study revealed a surge in marijuana use in weekend, nighttime drivers surveyed nationally and a troubling increase in fatal car crashes linked to pot in Washington state in 2014, two years after recreational marijuana was legalized there.

In 2013, for instance, eight percent of deadly accidents in Washington state involved drivers who had recently used marijuana. But that number more than doubled the following year to 17 percent.

“I can’t say that I’m shocked that there is a correlation,” said Irvine police officer Eddie Robinson.

“We go back to the substances that are currently legal: alcohol, prescription medications,” he said. “Same thing with marijuana. Marijuana will be no different. If not used responsibly and in moderation, bad things can happen.”

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Robinson has made hundreds of arrests of impaired drivers.

He is a drug-recognition expert who anticipates even more driving arrests if the recreational use of marijuana is on the ballot and becomes law in California in November.

“We already have so many drugs, medications that are already legal. And we see issues with impaired driving with those medications whether they be prescription, alcohol, what-have-you,” he said.

According to AAA, test results of THC, which is the chemical in pot that makes people high, aren’t reliable when determining impairment. For example, some drivers with low levels of THC may still be unsafe to drive.

Drug driving legislation is being considered by a California committee and will need to pass by the end of the month in order to move into the full Senate for a vote.

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If approved, it would give a police officer the authority to swab the mouth of a driver to test for the presence of drugs in his or her system.