In Pennsylvania, a person is guilty of DUI if he or she drives (1) with any amount of a Schedule I controlled substance under the Controlled Substance Act in his or her blood,* (2) with a metabolite of a schedule I substance in his or her blood,* (3) under the influence of a drug or combination of drugs to a degree which impairs his or her ability to safely drive, OR (4) under the combined influence of alcohol and a drug or combination of drugs to a degree which impairs the individual's ability to safely drive. 75 Pa. C.S.A. §§ 3802(d)(1)-(3) (West 2010).
NOTE: The Pennsylvania legislature has criminalized driving while a cannabis metabolite (which can linger in a person's system for weeks after ingestion) is present in an operator's system – even absent impairment. There is, however, a certain threshold for concentration of illicit metabolites that must be met before the results of a chemical test indicating cannabis metabolites can be introduced as evidence.
The Pennsylvania Bulletin, vol. 34, issue 7 initially specified the threshold level for THC or its metabolites at 5 nanograms per milliliter. However, this minimum threshold was amended to 1ng/ml in 2011, as noted in the April 30, 2011 edition of the Pennsylvania Bulletin. Any amount of cannabis metabolites at or above this level can be introduced as evidence of a per se violation of the statute proscribing operation with Schedule I metabolites, and can be introduced in a proceeding for prosecution for driving while impaired by drugs. However, the mere presence of metabolites are not enough to convict for offenses requiring impairment. In such a proceeding the state must show actual impairment.
The fact that a person charged with violating this chapter is or has been legally entitled to use alcohol or controlled substances is not a defense to a charge of violating this chapter.Id. § 3810.
Pennsylvania allows law enforcement to conduct sobriety checkpoints under the state and federal Constitution.
Com. v. Etchison, 916 A.2d 1169 (2007), affirmed 943 A.2d 262 – There is no equal protection violation in disallowing persons to operate with Schedule I drug or metabolite present in system; conviction does not rest on whether driver is impaired, but instead statute prohibits operation of a motor vehicle by any driver with Schedule I substances present. Pennsylvania court found all drivers are treated the same under statute.
Evidence failed to establish that defendant was under influence of drug or combination of drugs to degree which impaired his ability to safely operate his vehicle; expert witness testified under cross-examination that presence of metabolites was not indication of present impairment but only that substance was ingested sometime previously. Defendant was, however, convicted for operating with illicit metabolites in blood.
Com. v. Bishop, 126 A.2d 533, (1956) -- Statute making it unlawful for any person to operate a motor vehicle while under influence of intoxicating liquor, or any narcotic drug or habit producing drug, defines only one offense, namely, operating a motor vehicle while under an unnatural influence. 75 P.S. § 231(f). Where defendant was prosecuted for operation of motor vehicle while under influence of intoxicating liquor and he was acquitted, he could not thereafter be tried for operation of motor vehicle while under influence of narcotic drug based upon the same incident. 75 P.S. § 624(8).
Commonwealth v. Woodruff, 668 A.2d 1158, 1161 (1995) -- An intoxicated individual may use a vehicle as shelter as long as they do not drive or operate it, and are not in actual physical control of the vehicle. "A combination of the following factors is required in determining whether a person had 'actual physical control' of an automobile: the motor running, the location of the vehicle, and additional evidence showing that the defendant had driven the vehicle."
Pennsylvania has a per se drugged driving law enacted for cannabis, cannabis metabolites, and other controlled substances. (75 Pa. C.S.A. 3802(d) & 34 Pa.B. 919)
Under Pennsylvania's law, motorists with detectable levels of THC in the blood above 1ng/ml (reduced from 5ng/ml on April 30, 2011) are guilty of DUID.
Pennsylvania's law took effect in October 2003.