Meet Mats Järlström, the man who was fined for doing math without a license.

As Reason reported earlier this year, Järlström's wife was issued a citation in May 2013 after a red light camera in Beaverton, Oregon, caught her clearing an intersection a tenth of a second late. That small amount of time made Järlström—an electrical engineer by training—curious. He started researching traffic light timing in the city.

What he found suggested to him that there was a problem with the mathematical formula that Beaverton was using to time its yellow lights. He tried to bring his research to the city council but was repeatedly rebuffed. Next he brought it to the Oregon State Board of Examiners for Engineering and Land Surveying. Instead of investigating his claims, the board investigated Järlström. In 2016 the state fined him for daring to call himself an engineer. (Järlström had formal engineering training in his native Sweden and runs his own equipment calibration business, but he does not hold an Oregon engineering license.)

A lengthy (and ongoing) court battle ensued between Järlström, who believes he has a First Amendment right to promote his theory, and the Board of Engineering, which believes Järlström has the rights they say he does. Throughout this process, the board has used the threat of further fines to keep Järlström from publicly discussing his research. But on Tuesday, a federal judge granted an injunction against the board, preventing them from fining Järlström for talking while his court case grinds on.

In an interview with Reason, Järlström discussed his research, his yellow light theory, and how he managed to turn his wife's $260 ticket into a federal court case.

Järlström's work started with the simple filming and timing of the yellow lights at the intersection where his wife was ticketed.

"I shot different cycles of yellow lights," he tells Reason, "and it turned out that the lights were shorter than what the city of Beaverton said on their website."

Järlström hoped these findings might convince the court to let his wife's ticket slide. They didn't, and his wife ended up having to pay the fine. For many people, that would have been the end of it. But Järlström kept researching the issue, and he found what he thinks is a fundamental flaw in how traffic lights function not just in Beaverton but across the country.

In the United States, two types of laws govern how motorists should treat yellow lights. "Restrictive" laws require a driver to enter and clear an entire intersection before the light turns red. "Permissive" laws merely state that a driver must enter an intersection while the light is yellow. Most states take the permissive approach, but Oregon is one of 12 that have adopted restrictive rules.

Järlström says these different policies require different formulas for calculating how long lights should stay yellow. Under restrictive laws, yellow lights need both "warning time and the clearing time…you have the warning that you can enter, but the yellow is long enough so that you can travel through and exit the intersection." Permissive yellow lights can be shorter, because the driver doesn't have to clear the intersection before they change.

Beaverton, Järlström found, was using that shorter timing, even though it was enforcing a restrictive rather than permissive regulation. Drivers thus were not getting enough time to clear an intersection without being ticketed.

At that point, Järlström's recalls, "I started to look into the theory of the timing of the lights, digging into handbooks I could find, bought them on eBay and Amazon." He even reached out to Alexei Maradudin, one of the three scientists who came up with the modern yellow light formula back in 1959. (One of Maradudin's co-authors is Robert Herman, who also wrote the first paper on the big bang theory.) Järlström became convinced that Maradudin's formula was incomplete—that it failed to properly time lights for everything from right-hand turns to inclement weather conditions.

This, says Järlström, means that drivers are being ticketed by red light cameras—not just in Beaverton, but around the country—for traffic violations that were effectively outside of their control. "It's a physics problem. It's not anything to do with driver behavior….It's something we need to do on the engineering side."

His findings were strong enough to win him a speaking gig at the 2015 Institute of Traffic Engineers' national conference and a spot on 60 Minutes. He even won over Alexei Maradudin—the very man whose theory he was criticizing.

But he didn't win over the Beaverton city council. Järlström went before them 13 times, but he made little headway. He suspects that wasn't because there was a problem with his equations. "If I come in there and tell them that something is wrong and has been wrong for a long time, you see liability issues, paying back fines, etc.," he says. "So obviously they are fighting with their teeth to get me out of there."

Järlström sued the city of Beaverton for refusing to listen to his theory, but his case was dismissed on the grounds that he didn't have standing. So Järlström turned to Oregon's State Board of Engineering, asking them in September 2014 to look into the City of Beaverton's yellow light timings. Because he referred to himself as an engineer in his letter to the board, it launched a two-year investigation that ended with it issuing a $500 fine.

"They wanted to kill the messenger," Järlström says. "They just wanted to shut me up."

Järlström paid the fine. But rather than let the matter end there, he then sued the State Board of Engineering for violating his First Amendment rights. The board, Järlström notes, has yet to substantively dispute any of his findings. Instead it's challenging his right to publicize them.

Järlström may well be wrong in the claims he is making about the nation's yellow lights. I am certainly in no position to judge his arguments on the mathematical merits. But he has presented a plausible hypothesis, supported it with credible evidence, and enthusiastically engaged both his engineering peers and the general public on an issue of civic importance.

In a different world, the engineering community would be engaging Järlström right back, probing his findings for their merits and deficiencies. That's what science looks like. That's what a free society looks like. Instead, Järlström is locked in a legal battle over whether he even has the legal right to present his research.