Next problem is to get rid of the archaic zero-tolerance BS:
"Pennsylvania has a very simple marijuana DUI law zero tolerance (one nanogram of active THC per milliliter of blood). That means that if you have any amount of marijuana metabolite in your system, you may be guilty of DUI.
However, to charge someone with DUI based on impairment by marijuana, the person must have a concentration of a marijuana metabolite of at least one nanogram per milliliter (ng/ml) of blood. Pennsylvania adopted this new lower threshold in 2011, as it was previously five ng/ml."
Basically, they test for metabolite, so even if you're hanging with friends 3 weeks ago, it could mean automatic license suspension for a year.
...and get this... EVEN APPLIES IF YOU ARE STATE APPROVED FOR MEDICAL MJ !!!!
Even if you have a legal prescription for medical marijuana, you can still get a marijuana DUI in Pennsylvania.
"Pennsylvania is among the handful of U.S. states that have adopted per se DUI laws for marijuana. Per se laws make it illegal to drive with a drug in your body that exceeds a specified limit. You cannot drive with any amount of marijuana metabolite over one nanogram per milliliter in your system.
The key thing to understand about the per se law is that prosecutors do not have to show that you were in any way impaired while driving. Just the presence of marijuana over one nanogram per milliliter in your bloodstream can lead to a conviction. Police officers dont even have to provide evidence of impaired driving to make an arrest. All they need is a reasonable suspicion that a driver is under the influence of drugs."