She begins to calculate how much it will cost to bail herself out of jail for driving with a suspended license.

The single mother works the night shift in a warehouse eight miles away from home. The buses stop running for the night before her shift ends. She spends all the money from her paychecks on rent, food, and otherwise supporting her 10-year-old son and elderly grandmother, who live with her in Birmingham, Alabama.

Cook cannot afford the $456 in traffic fines and court costs that got her license suspended in the first place. But she must drive to get to work, take her son to school, and travel to doctor’s office appointments.

“Driving on a suspended license makes me feel like I am a criminal, even though my life largely consists of going to work and caring for my family,” said Cook, a plaintiff in a federal lawsuit the SPLC filed today against the state of Alabama.

The lawsuit challenges a law that allows a person’s driver’s license to be suspended for unpaid traffic tickets, without taking into account the person’s ability to pay. The law is unconstitutional, and harms thousands of low-income families across the state, according to the complaint.

The licenses of roughly 23,000 Alabama residents are currently suspended for nonpayment under the rule.

“It is my hope that this lawsuit will result in a clearer path for me and others in a similar situation, to get our driver’s license back,” Cook said. “No one should have their license suspended because they don’t have enough money to pay traffic tickets.”

Alabamians impacted by this punitive practice are stripped of their ability to support themselves and their families, as driver’s licenses are crucial to securing and maintaining employment, driving children to school, and meeting basic needs, according to the complaint. The SPLC seeks a preliminary injunction to halt the practice while the case is before a federal court.

The lawsuit asks the court to declare the law unconstitutional, and to issue an order blocking the Alabama Law Enforcement Agency (ALEA) – a state agency that coordinates public safety in Alabama – from enforcing any order suspending driver’s licenses for nonpayment under the law. It also asks the court to require ALEA to reinstate any driver’s license previously suspended solely for nonpayment.

“A suspended driver’s license has disastrous implications for individuals living in poverty,” said Micah West, a senior staff attorney for the SPLC. “The U.S. Constitution prohibits the state from suspending a person’s driver’s license without first determining their ability to pay. Through this lawsuit, we hope to end this illegal practice in Alabama.”

The lawsuit describes how, under an existing rule of criminal procedure, Alabama courts routinely suspend driver’s licenses for nonpayment of traffic tickets without prior notice, an inquiry into an individual’s ability to pay, or an express finding that nonpayment was willful, as required by the Due Process and Equal Protection Clauses of the U.S. Constitution.

The Alabama Law Enforcement Agency carries out these suspensions and refuses to reinstate driver’s licenses until an individual has paid all outstanding fines and costs to the court.

That’s what happened to Sharon Motley, another plaintiff in the lawsuit. The Montgomery County District Court ordered Motley to pay $310 for a traffic ticket and court costs in 2013, even though she was unemployed at the time.

When she failed to pay, her driver’s license was suspended. But neither the court nor ALEA asked about her inability to pay before doing so. Her driver’s license is still suspended to this day.

“I have been struggling financially for many years,” Motley said. “When my license was suspended in 2013 because I couldn’t afford to pay a traffic ticket, I was devastated. I completely lost the ability to legally drive and secure a well-paying job that would allow me to pay my bills and the traffic ticket. I want to get to a better place financially so that I can afford to pay the traffic ticket, but I can’t do that without a valid driver’s license.”

Individuals with suspended driver’s licenses often risk driving to maintain their livelihood and support their families, the lawsuit states. If stopped by police, they could face additional penalties – including up to six months in jail and hundreds of dollars in court costs.

Earlier this year, the SPLC filed a lawsuit challenging similar practices in North Carolina, and last year reached an agreement with Mississippi that will lift failure-to-pay suspensions for over 100,000 people.

Lawsuits have also been filed in Tennessee, Michigan, California and Virginia, challenging the suspension of driver’s licenses for nonpayment.