Outlines evidence suggesting the Standardized Field Sobriety Test can be supplemented with other tests and observations to help law enforcement officers detect potential cannabis impairment in drivers.

Key findings:

• After alcohol, cannabis is the most frequently detected substance among drivers arrested for impaired driving. 
• There’s a need for a brief field test that could be easily used by law enforcement at roadside to identify drivers whose ability to operate a vehicle may be adversely affected by cannabis use.
• Sensitivity of the Standardized Field Sobriety Test (SFST) to detect cannabis impairment is considerably lower than that for detecting alcohol impairment.
• Adding the finger-to-nose (FTN) test and assessing (1) head movements and jerks and/or (2) eyelid tremors during the SFST produced a test battery with enhanced sensitivity to cannabis impairment.