Here are her comments sent out via

Below her comments  you ‘ll find the document she is referring to.

This is the most recent NHTSA report on DWI/Marijuana. It’s a 2017 report to Congress. It’s remarkable that NHTSA would author this document as the conclusions dispel both the DRE/ARIDE ability to determine that a person is driving while impaired by marijuana.

1.       There is no psychophysical test to determine driving impairment by marijuana.( By implication as we already know SFST are only for alcohol.) There is no impairment standard for drivers under the influence of marijuana. In fact according to this report “ available research does not support the development of such a psychomotor, behavioral or cognitive test that would be practicable or feasible for law enforcement to use at this time. (This report more than implies that a DRE cannot determine driving impairment by marijuana)

2.       Spells out that ARIDE police should contact a DRE to determine if a defendant is impaired by marijuana.

3.       Then contradicts itself by stating “All most all the DRE signs and symptoms for marijuana are not based on driving impairment.” (Green tongue, HGN, red eyes)

4.       Levels of THC decrease by 80-90% in blood within 1 hr. of use.

5.       There is no set level of THC to determine impairment. Impairment by THC is subjective.

6.       Studies are undecided as to impairment of psychomotor task, cognitive and executive functions by marijuana. Some yes some no.

7.       Discusses new screening tests that detect TCH presence & levels but concludes that they have yet to be determined to be accurate or reliable.

Cheryl Brooks, Assistant Defender

Appeals Division

Defender Association of Philadelphia

1441 Sansom Street

Philadelphia PA 19102

(267) 765-6942

FAX: (267) 765-6978


NHTSA Report to Congress on DUI Marijuana
NHTSA Report to Congress on DUI Marijuana