Once was a time when marijuana was illegal that the exact definition of being “one toke over the line,” as the old song went, was a philosophical issue probably best left to people within reach of that limit, wherever it might be.

Now, it’s a serious and sobering question, and it’s one lawmakers need to figure out quickly.

Prompted by a task force working in light of legalized marijuana in Massachusetts, Gov. Charlie Baker filed legislation in January to give clearer authority to police and the Registry of Motor Vehicles when it comes to keeping intoxicated people off the roads. Several proposals were packed into his bill — including training for judges and police — but the central idea was to automatically suspend the driver’s license of someone believed to be operating under the influence who refuses to submit to a test of their spit, blood or urine for THC.

If it sounds familiar, the rules mimic those for people suspected of drunken driving who refuse to submit to a Breathalyzer test.

But Baker’s bill is bogged down — it hasn’t even had a hearing, as of the first of this week — and now the state’s Cannabis Control Commission is opening the door not only to retail pot sales but cafes where patrons can buy and consume marijuana products.

Earlier this week, Baker and others urged lawmakers to act on the impaired driving bill before those businesses open and people go out on the town for a pot brownie or two before climbing behind the wheel. The governor told reporters, “I think the two of them go hand in hand.”

Of course they do, and Beacon Hill needs to work fast. Enforcement of impaired driving is already a concern since voters made the possession and sale of limited amounts of marijuana legal. The problem will only get more pressing as places open for people to publicly gather and consume together.

In fairness, there are good reasons this bill should be carefully reviewed. THC’s effects are not the same as alcohol’s. Proving someone is too stoned to drive likely involves more than just the results of a saliva test.

That said, other states with legal weed have passed similar laws. Police need some mechanism to stop and prosecute people with no business driving, and a biological test is an important part of that.

Procrastination is no solution. It’s past time that lawmakers drew the line.

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