A sign warns drivers of the red light camera at the intersection of Irving Park Rd. and Kedzie. View Full Caption The Expired Meter.com

OTTAWA — A class-action lawsuit that aims to end the city's red-light camera program — and possibly lead to refunds to drivers for every ticket issued since it started in 2003 — was argued before the Illinois Supreme Court Wednesday, but justices gave no indication which way they might rule.

Attorney Mike Reagan told the court that the city did not have the legal authority to start using cameras in 2003 because the Illinois General Assembly had not passed a law specifically allowing this type of traffic enforcement.

Mike Brockway breaks down the case on DNAinfo Radio:

Reagan also argued that the city, by using the cameras, actually violated Illinois laws requiring uniform traffic rules statewide, which applies to such things as the color of stop signs, traffic lights and other rules of the road.

"The city lacked the power to enact this ordinance," Reagan said. The city law "destroys uniformity and uniform enforcement of traffic laws."

State lawmakers did not OK automated red-light cameras until 2006, but then restricted their use to just eight of counties, including Cook, the collar counties and counties near St. Louis.

Reagan said that law violated the state constitution because state laws must apply to the entire state.

But Chief Justice Rita Garman asked Reagan, "What about the fact that the eight counties are contiguous to our most populous places?"

Reagan noted that some of the towns in the eight counties allowed to use the cameras are actually smaller than cities like Champaign, Rockford and Peoria, which aren't authorized to have them under the law.

The historic Ottawa courthouse where the Illinois Supreme Court heard oral arguments in a case challenging the validity of the state and City of Chicago's red light camera laws. View Full Caption The Expired Meter

City lawyer Kerrie Maloney Laytin said the law covered the eight counties where the sheer volume of traffic makes it more difficult to enforce red lights using just police.

"This is where the red light problem is at its zenith," Maloney Laytin said.

The city has also contended it had the right to establish the program under home rule authority, which allows cities with populations over 25,000 to pass laws that might normally be issued at the state level.

The original class action lawsuit, Keating v. City of Chicago, was filed in Cook County Circuit Court in 2010 but was dismissed in 2012 and upheld on appeal last year.

Chicago has the nation’s and perhaps the world’s largest red light camera enforcement program. At its peak it had 384 cameras at 191 intersections and has generated over half a billion in revenue for the city over the past 11 years since its inception in 2003.

While neither side broached the subject of the fines the city has collected over the years, depending on how it rules, the Supreme Court could open up Chicago to the possibility of having to refund tens if not hundreds of millions of dollars in red-light camera fines, plaintiffs hope.

Elizabeth Keating, one of the plaintiffs suing the city, said the city's program was unfair.

"I'm representing an astonishing large number of people who feel, like me that they have been unjustly ticketed," Keating said. "I really hope the court looks at our filings and finds that citizens are being unjustly prosecuted."