In a world where substances such as marijuana and ecstasy are either legal or will soon be, we must update enforcement of driving while intoxicated.

DRUID tests for all levels of impairment — even exhaustion, which can be as dangerous as drunk driving — and scales impairment on a .08 intoxication scale.

Harvard Ph. D Michael Milburn designed DRUID, an app that tracks impairment, whether from marijuana, alcohol, or fatigue, and calculates a number based on the alcohol limit, being .08.

DRUID measures reaction time, decision making, hand-eye coordination, time estimation, and balance, and then statistically integrates hundreds of data points into an overall impairment score. DRUID takes just 2 minutes and only has to be purchased once.

“Cannabis is not being invented, just legalized — people have been driving stoned for decades. Cannabis-impaired driving is talked about a lot these days,” Harvard economist Michael Milburn said. “No one should drive impaired, but actual impairment should be measured, and the level of impairment from cannabis that is criminalized should be the same as the level of impairment for the .08 blood alcohol level.”

The National Highway Traffic Safety Administration states, “It is difficult to establish a relationship between a person’s THC blood or plasma concentration and performance impairing effects. Concentrations of parent drug and metabolite are very dependent on the pattern of use as well as dose.” (NHTSA, 2016).

Marijuana can stay in a user’s system for up to 90 days contingent upon use and body fat percentage, creating a nightmare for those who legally smoke marijuana and are accused of DWI.

DRUID is downloadable by anyone, meaning anyone with a smartphone can potentially test their impairment before driving or working heavy machinery.

San Diego is a step ahead: California gave them $2 million to develop an app that measures marijuana impairment. Like alcohol, marijuana isn’t interpersonal: a hit that could extremely intoxicate one person could not even get another person high.

If you’re too intoxicated to drive, don’t fret. DRUID has links to ride-sharing companies, food delivery, games, movies, and even websites to make art and memes.