Marijuana dispensaries seem as common these days as bars, which is why some lawmakers are looking for new and better ways to bust people who drive while high. A proposal that is likely to surface soon at the state Capitol could use a concept similar to the blood-alcohol limit to test if drivers are under the influence of THC, the psychoactive substance in marijuana.

Already under current law, drivers suspected by police of being high on pot or other drugs must submit to a blood test or face having their license suspended. The new law would “bring some clarity” in establishing a standard by which officers could presume a driver is impaired by marijuana, Representative Claire Levy, the Boulder Democrat expected to sponsor the legislation, tells The Denver Post. A proposal by the Colorado Commission on Criminal and Juvenile Justice would set the THC threshold at five nanograms per milliliter of blood—the level of impairment, officials say. But Sean McAllister, a lawyer who serves on the commission’s drug policy subgroup, says some users of medical marijuana have a higher THC tolerance than others and may not become impaired at the level lawmakers may set.

Still, recently noted statistics paint a tragic picture. Some form of marijuana shows up in eight percent of all the drivers killed in Colorado, claims Arapahoe County Sheriff Grayson Robinson. “Anytime that they’re in an impaired state while driving a motor vehicle, we’re all in danger,” Robinson tells 7News. If passed, the penalties would be similar to those of the state’s drunken-driving statutes.