​A bill increasing restrictions on people in Colorado who drive after using marijuana took another step forward in the legislative process on Tuesday.

The Denver Post. But the approval of House Bill 1261 by the state House of Representatives had some attendant drama, including a skirmish among the bill’s two sponsors, reports John Ingold at

HB 1261 [PDF] would create a limit on the blood-THC levels of drivers. Anybody who tests above an arbitrary amount, five nanograms per milliliter, would be considered too high to drive, much as someone with a blood-alcohol level above 0.08 percent is considered too drunk to drive.





​Law enforcement supports the bill, claiming it brings specificity to existing laws against driving while stoned. But the proposal has gotten a lot of criticism from medical marijuana patients and advocates, who maintain that the five-nanogram limit is too low for patients who are accustomed to high levels of THC.

It’s hard to quantify a “one size fits all” limit for THC levels in the blood, just as it’s difficult to know how long patients should wait to drive after using marijuana. There is currently no easy way for patients or other marijuana users to figure out what their THC levels are.

The bill’s supporters claim studies conclude that people with levels above five nanograms — if not lower — are impaired. Officers would supposedly need to have “good reason” to suspect drivers of being drugged before they would be forced to have their blood drawn.

Tuesday’s fight in the House erupted when Rep. Claire Levy (D-Boulder), one of the bill’s sponsors, proposed raising the blood-THC limit to eight nanograms, saying it is best to be cautious.

“I became concerned that we were going to convict people and take their licenses away when they were not impaired,” Levy said.

But her proposal angered several other legislators, including her co-sponsor, who claimed the five-nanogram limit had been “extensively discussed.”

“There’s nothing to support that eight is the right level,” claimed Rep. Mark Miller (R-Colorado Springs), who is the bill’s other sponsor.

Rep. Bob Gardner (R-Colorado Springs) got so angry he proposed lowering the limit all the way to two nanograms before backing off.

The House then voted down Levy’s eight-nanogram proposal and passed the bill with the five-nanogram limit, after taking a procedural step that will make it harder in the future for lawmakers to tinker with the limit as the bill makes its way through the Legislature.

HB 1261 needs one more vote in the House before going to the Senate, where it must survive at least three votes to make it to Governor John Hickenlooper’s desk.