PHILADELPHIA (WPVI) -- Marijuana laws are evolving and vary from state to state, especially when it comes to DUI enforcement.
In Pennsylvania and Delaware, the DUI laws are called "zero tolerance," meaning you could get charged with DUI with any amount of cannabis in your system whether impaired or not.
Critics, including Pennsylvania State Representative Chris Rabb, believe that's unfair.
Rabb currently has a bill that would change the law here in Pennsylvania and require proof of impairment for DUI and cannabis.
In mid-February, Representative Rabb agreed to take a drug test to prove his point.
"I feel fine to do anything because I'm not impaired," said Rabb, who takes cannabis tinctures at night to help with sleep.
Tinctures are a liquid infused with cannabis.
"I take a third of dropper under my tongue and swallow it," he said.
It has been more than 12 hours since he took his medical marijuana.
"I wake up feeling bright-eyed and bushy-tailed with no symptoms," he added.
Rabb is among nearly a half million Pennsylvanians who have a medical marijuana card.
He said he takes the tinctures after suffering Post Traumatic Stress Disorder (PTSD) after being just steps away from a brutal murder outside a corner store in 2016.
"Those of us who were there on the scene feared that he would kill us all," he said.
Dr. Brooke Worster is a professor of Medical Cannabis Science and Medicine at Thomas Jefferson University.
"Do you think states like Pennsylvania and Delaware should move away from no tolerance and have proof of impairment?" asked Chad Pradelli.
"I do," said Worster.
Her opinion is the occurrence of THC in the bloodstream doesn't necessarily equate to impairment.
"So you're left with a lot of guesswork, and especially for people in the field, in terms of what is safe and what isn't, it's a real issue," she said.
States including New Jersey require proof of impairment to be charged with DUI for cannabis.
Currently, there is no roadside test or technology to determine levels of THC, the psychoactive ingredient in marijuana that gets you high and prove impairment.
But like other states, Pennsylvania State Police has seen a surge in drug DUIs that includes marijuana.
"If they have taken it within 24 hours, they're still impaired," said Corporal John Witkowski.
Witkowski runs the state police DUI and Drug Recognition Agency responsible for spotting drivers impaired on drugs including marijuana.
He said there's a misconception that marijuana and driving are not a dangerous combination.
"They think they are safe to drive because it has that word medical attached to it," said Witkowski.
Rabb said he is not promoting unsafe driving, but since THC levels could appear in your system days after, using the current law doesn't make sense.
"If you drive impaired, there should be consequences," he said. "I don't care what's in your system."
But Representative Rabb said the results of his drug test results also prove his point.
"Said I was full of cannabis. And I've been told I am full of a lot of things (laughs), but I never saw a test that said I had cannabis."
He said he took a serious risk taking a drug test for our story, exposing him to possible DUI, despite saying he never drives impaired.
"I'm not a risk taker by nature, but I think there's so few people who would be comfortable talking about this on-air without serious repercussions," he added.