It can start with a couple of traffic tickets. Unable to pay the tickets right away, a driver becomes saddled with late fees, fines and court costs. Soon, the driver may be taken off the road indefinitely.

More than 40 states allow the suspension of driver’s licenses for people with unpaid criminal or traffic court debt.

But now, advocates across the country are pushing to change that, arguing that such laws are unconstitutional because they unfairly punish poor people and violate due process by not giving drivers notice or an opportunity to show they cannot afford to pay the fees.

Lawsuits have been filed in at least five states over the past two years.

“It’s not that I don’t want to take care of what I owe. I really wish I could,” said Brianna Morgan, a single mother from Petersburg, Virginia, who hasn’t had a license in three years because she owes more than $400 in traffic fines and court costs from traffic violations and a disorderly conduct citation.

“I really don’t have a way to pay it,” said Morgan, who supports herself and her three children on a monthly disability check.

Advocates had a victory this week in Tennessee, where a federal judge ruled that a law that allows the state to revoke the licenses of low-income people with unpaid court debt from past criminal convictions is unconstitutional.