ST. PAUL, Minn. -- A state lawmaker has introduced a bill that would bring stiffer penalties to those convicted of blocking a freeway during a protest, changing the offense from a simple misdemeanor to a gross misdemeanor.

Rep. Kathy Lohmer, a Stillwater Republican, says she's heard from many constituents who support the idea of creating more of a deterrent for those who shut down highways to make a point.

"People worry about if they're in an ambulance trying to get to the hospital, they're in a car trying to get to the airport or trying to visit someone who's sick and dying, they can't get where they need to go," Rep. Lohmer told KARE.

Blocking freeways has become a common tactic for demonstrators in the Twin Cities in the aftermath of police shootings of unarmed black men. It's an effort to disrupt the lives of motorists, and force them to think about issues they might otherwise avoid altogether.

"I am very concerned about the safety of the protesters, the safety of the police and the safety of the public."

Currently it's a simple misdemeanor to violate that part of Minnesota's public right of way statute, and misdemeanors generally carry a maximum penalty of 90 days in jail and a $1,000 fine. Lohmer's bill, House File 55, would raise the crime of blocking a public highway to a gross misdemeanor, which carries a maximum penalty of a year in jail and a $3,000 fine.

"Something that's punishable by up to a year in prison for everyone that goes onto a highway is just out of proportion to what the conduct is," said Teresa Nelson, the legal director of the ACLU of Minnesota, which has gone to bat for the First Amendment free speech rights of the highway protesters.

She said there's not much case law specifically about interstate protests, but courts have generally upheld the rights of protests to take to the streets.

"What's especially troubling about this is that it seems the legislature is reacting to groups that are expressing a particular message, and that message typically is 'black lives matter'. It seems like retaliation against the messengers."

Rep. Lohmer, who has a son in the Minnesota State Patrol, said her concern is purely about public safety.

"I’ve been involved in situations where I’ve wanted to get my message out. I totally support and believe in that. It’s just the place they’re choosing to do it," she said.

"The freeway’s really not a public place. You need to have a driver’s license, and licensed vehicle to be on a freeway. And that can be taken away from you if you’re not a good driver or don’t have the proper licensure on your car."

Most recently protesters took possession of Interstate 94 in St. Paul in July of 2016 after a Falcon Heights officer shot motorist Philando Castile during a traffic death. Police reported that 21 officers sustained injuries in the effort to control the scene.

This week a Ramsey County judge dismissed gross misdemeanor rioting charges against 47 protesters, but they still face misdemeanor charges of unlawful assembly and disorderly conduct. District Judge G. Tony Atwal ruled that there was insufficient evidence that the 47 defendants had been the same protesters who threw rocks, bricks, concrete chunks and bottles at officers responding to the freeway shutdown.