THE NEW YORK TIMES – In Colorado, where America’s experiment with legal recreational marijuana began a little more than a decade ago, a team of federal scientists has been paying regular cannabis users to get stoned.
This unconventional line of research — which includes vans outfitted with hippie tapestries and a sleek car simulator — seeks to tackle what road safety experts regard as a serious blind spot as marijuana use grows nationally.
Law enforcement officials lack tools to detect cannabis-impaired driving as reliably as they can identify people who get behind the wheel drunk.
Only a few states routinely test the blood of drivers involved in serious accidents for marijuana, and as a result, little is known about how cannabis use is affecting road safety.
Police officers generally need a warrant to compel a driver suspected of being impaired to provide a blood sample.
Even when blood samples are analyzed, tests cannot reliably establish whether a person last used marijuana hours before the accident or several days prior, making the tests an imprecise gauge of impairment.
Complicating matters, state laws on cannabis-impaired driving are inconsistent and confusing, which has made them difficult for the police to enforce and for motorists to understand.
“We’re kind of painting the plane as we fly it when it comes to cannabis liberalization,” said Jake Nelson, the director of traffic safety advocacy and research at AAA, the automobile drivers group, which opposes the legalization of recreational cannabis. “Public health and safety has been more of an afterthought … ”
