# Cannabis edible consumption and driving impairment > Live situation record from CLSTR: https://clstr.news/situations/cannabis-edible-consumption-and-driving-impairment > Updated: 2026-09-05T06:28:00.000Z. Sources: 5. Developments: 2. A study published in ‘JAMA Network Open’ has identified that cannabis edibles, such as THC gummies, significantly impair driving ability even several hours after consumption. Research conducted at a Canadian hospital involving 40 participants found that doses of 10mg and 20mg led to increased lane deviation, slower reaction times, and inconsistent vehicle speeds. A critical finding of the research is that impairment persisted two to five hours after ingestion. Notably, blood THC concentrations in impaired participants averaged between 1.6 ng/mL and 3.4 ng/mL, which falls below the 5 ng/mL threshold used by law enforcement in several jurisdictions to determine impairment. This discrepancy suggests that current roadside enforcement limits, largely developed for inhaled cannabis, may fail to detect impairment caused by the delayed absorption and prolonged effects of oral consumption. In the United States, the American Trucking Associations has raised concerns regarding public safety and the potential for weakened drug testing protocols following the reclassification of marijuana to Schedule III. ## Timeline ### 2026-09-05: Cannabis edibles impair driving even when blood THC levels are low A study finds that cannabis edibles can impair driving, including lane control and reaction times, even when blood THC levels fall below legal limits used for roadside enforcement. 2 sources. https://clstr.news/cluster/cannabis-edibles-impair-driving-even-when-blood-thc-levels-are-low ### 2026-09-03: Cannabis edibles impair driving ability hours after consumption, study finds A new study shows cannabis edibles significantly impair driving skills, including lane control and reaction times, even hours later and at THC blood levels that may fall below legal driving limits. 3 sources. https://clstr.news/cluster/cannabis-edibles-impair-driving-ability-hours-after-consumption-study-finds --- Cite as: Cannabis edible consumption and driving impairment. CLSTR, https://clstr.news/situations/cannabis-edible-consumption-and-driving-impairment