Protesters blocked all four lanes Friday morning of southbound I-75 near Mack in Detroit.
Michigan State Police eventually pulled them over just before the I-375 split and helped direct traffic.
The protesters have been on area freeways before rallying against Detroit's emergency manager. The cars drive slowly in the lanes, backing up and blocking the flow of traffic.
Ayana Rhodes was one of the drivers who was slowing traffic. She explained why she and the others took their protest to the freeway.
"We just wanted to bring some attention to let everyone know, including the citizens of Detroit, more specifically the state of Michigan that our due process and civil liberties are not negotiable," Rhodes said.
In March, Gov. Rick Snyder appointed Kevyn Orr to take over the finances of the largest city in the country to come under state oversight.
The city has a $327 million budget deficit and more than $14 billion in debt.
Since then, several protests, including those featuring prominent leaders like Rev. Al Sharpton, have been held in the city.
Rhodes said the protesters timed Friday's action to coincide with traffic heading to opening day.
"We knew there would be a lot of people who would be out, so we definitely wanted to bring some attention, so today would be the kind of day to get our message out there and get our message across," Rhodes said.
The protesters have staged other freeway slowdowns and Rhodes says the actions will continue.
"We are going to continue to do what we need to do because this is something that needs to be addressed and needs to be said and we are not going to give it up until our voices are heard," Rhodes said.
State police issued citations to four of the protest drivers for careless driving. That is a violation that could put three points on their licenses.
Officers said if those protesters are stopped again taking the same action, the citation would be for reckless driving. That is a more serious offense.