THC and Cannabis Dosages: "THC is the major psychoactive constituent of cannabis. Potency is dependent on THC concentration and is usually expressed as %THC per dry weight of material. Average THC concentration in marijuana is 1-5%, hashish 5-15%, and hashish oil ³ 20%. The form of marijuana known as sinsemilla is derived from the unpollinated female cannabis plant and is preferred for its high THC content (up to 17% THC). Recreational doses are highly variable and users often titer their own dose.
Statistics and data relating to operating a vehicle while under the influence of an intoxicant (DUII), also referred to as drugged driving, drunk driving, driving under the influence (DUI), or driving under the influence of drugs (DUID).
DRUID Project Evaluation of Oral Fluid (Saliva) Testing Devices for DUI Enforcement
Impairment Thresholds for Blood THC Level Compared With Blood Alcohol Content: "To combat drug-driving, most countries either operate a zero tolerance policy or take into account degree of impairment, sometimes in a two-tier system. Legal limits may be set low, at the limit of detection, or higher to take effects into consideration. For example, while the project set a detection limit of 1 ng/ml in whole blood for THC in the roadside surveys, it was found that 2 ng/ml THC in whole blood (3.8 ng/ml THC in serum) seems to cause impairment equivalent to 0.5 g/l BAC. Such equivalents could not be calculated for other drugs. It is not realistic to develop cut-off limits for all substances."
Thresholds for Serum THC Level Compared With Blood Alcohol Content
State Drug Per Se Laws: "Currently, there are 15 States where it is illegal per se to operate a motor vehicle with certain drugs in one’s system.
"Three of those States (Nevada, Ohio, and Virginia) have determined that driving with specific cutoff levels of certain prohibited drugs or substances other than alcohol is a per se violation of its DUI statute.
Marijuana and Driving - More Data Needed: "The decreased speed during the simulated drive could be interpreted as an attempt to compensate for perceived cognitive impairment, Alternatively, marijuana may not have affected decision making and judgment and the reduction in speed would improve safety margins, While the clinical significance of a 3% to 5% decrease in speed may be questioned, previous research suggests such a decrease will result in approximately a 7% decrease in all injuries and a 15% decrease in fatalities (Nilsson 1981), Use of an alternate task design in which subjects are r
Cannabis and Driving Impairment: "The present study's subtle finding of decreased speed under the influence of acute marijuana is generally consistent with the literature, which has found that marijuana's effects on driving can be subtle.
Cannabis Use and Motor Vehicle Accident Risk: "Our primary analysis looked at the risk of a motor vehicle collision while under the influence of cannabis and included all nine studies (relating to 49 411 participants). The pooled risk of a motor vehicle collision while driving under the influence of cannabis was almost twice the risk while driving unimpaired (odds ratio 1.92 (95% confidence interval 1.35 to 2.73); P=0.0003); we noted heterogeneity among the individual study effects (I2=81%).
Non-Driving Reasons for License Suspension: "According to a survey of State motor vehicle agencies and a review of State statutes conducted for this study, all 50 States and the District of Columbia have laws that permit the State motor vehicle agency and/or the courts to withdraw driving privileges for at least some non-driving reasons.
Prevalence of Drug Use Among Drivers: "Analyses of the oral fluid samples obtained from daytime drivers indicated an overall drug use prevalence of 11 percent, and for nighttime drivers, 14.4 percent (Table 19). This includes illegal, prescription, and over-the-counter drugs combined. This overall difference between day and night is statistically significant (p < .01).