Cindy Tregilgas was on her way home from work a few years ago when she encountered a traffic signal she’d never seen before: a flashing yellow arrow.

Tregilgas was waiting at Manning Avenue and Hudson Road in her Honda Accord, just about a mile from her house in West Lakeland Township, when a yellow left-turn arrow started flashing.

“There was no sign, no explanation,” said Tregilgas, vice president of finance at Dakota Technologies Co. in New Hope. “I was, like, ‘What’s this? Why is that flashing at me? What does that mean?’ ”

Tregilgas said her confusion almost got her killed.

“In my experience, if a signal is flashing, that means everybody has to stop, and then you take turns,” she said. “That’s what I had been used to, so I wasn’t quite sure what to do. It’s that split-second thing. I stopped, and then I thought, ‘Oh, I’ll take my turn to go now,’ and somebody was coming.”

A few days later, a driver nearly struck her while turning on a flashing yellow arrow at the same intersection. “They basically made the same mistake I did,” she said.

The near-misses frightened Tregilgas so much that she complained to the Minnesota Department of Transportation.

Because of her concerns, MnDOT officials changed the agency’s guidelines. Signs saying “Left turn yield on flashing yellow arrow” must be mounted on signals’ mast arms for a minimum of six months after the arrow signal is installed on a state road.

Washington County transportation officials complied with the state guidelines for a couple of years, but then started putting the signs in the median instead of next to the signal on the mast arm — a move that Tregilgas said reduces their effectiveness.

“Look at this one. You can’t even see it behind the ‘Do not enter’ sign,” Tregilgas said during a tour of the 10th Street North and Helmo Avenue North intersection in Oakdale. “I’m not against the signal; I just want a sign to go with it because it gets confusing. It’s just that instant reminder when you have to make that split-second decision when you’re driving. Unless you see a sign up on the arm, how will you know this sign goes with that signal?”

Signs placed in the median are not in a driver’s “natural line of sight,” she said.

“When you come to an intersection, you are looking at the light and the other cars around you,” she said. “Signs need to be easily visible, not something drivers seek out.”

COUNTY SAYS SIGNS AREN’T NEEDED

Tregilgas asked Washington County officials this spring to implement a policy to make county intersections consistent with MnDOT guidelines.

“Though many cities and counties follow the manual, others do not,” she told county board members in April. “This inconsistency is confusing to drivers, which can lead to accidents.”

Washington County Engineer Wayne Sandberg said flashing yellow arrows, which speed the turns for anyone driving in off-peak hours, are safe and efficient.

“I’ve got some younger kids who are driving now, and they are taught in driver’s ed what the flashing yellow arrow means,” he said. “Most drivers have seen this, and they understand what it is. In fact, it’s the No. 1 request we have in Washington County that people want more flashing yellow arrows. I consider it, at this point, ubiquitous to driving. It’s well-known, it’s understood, and, therefore, you no longer need the educational component that these signs were trying to accomplish 10 years ago.”

Washington County has stopped putting up signs where the arrows are installed and plans to start removing the ones that are there, Sandberg said.

“People understand how they work,” he said. “We don’t sign rules on the road. You can imagine if we signed rules on the road, we’d have them everywhere.”

Although Tregilgas says drivers are confused, “we’re just not seeing it,” Sandberg said.

Commissioner Gary Kriesel said drivers understand how flashing yellow arrows work and do not need to be signed.

“Drivers, I think, are fully educated,” he said. “They get it. They are very popular. They are so doggone popular, everyone wants one. They are a great way to manage flow.”

STATE: FEWER CRASHES WITH FLASHING YELLOWS

MnDOT began installing the flashing yellow arrows in 2009 after the Federal Highway Administration authorized their use. There are at least 400 flashing yellow arrows now in place around the state, said Jerry Kotzenmacher, MnDOT’s traffic signals specialist.

Kotzenmacher said drivers have fewer crashes with flashing yellow left-turn arrows than with traditional yield-on-green signal configurations.

“To me, there’s no question that they are safer,” he said. “People understand the flashing arrow more than they understand a green ball for a left turn.”

Traffic engineers like them because they provide more options for controlling variable traffic volumes. They can turn them on and off depending on time of day, Kotzenmacher said.

“When … it’s the middle of the night, and the driver is stuck there — and that was a big complaint we got in operations: ‘Why am I waiting here when there is nobody coming and it’s the middle of the night?’”

Signs alerting drivers to the arrows can be confusing, Kotzenmacher said, because when drivers see the signs when the arrows are turned off, they wonder what the signs are referring to.

BUT SHE PERSISTS

Tregilgas is not deterred.

She is lobbying the Minnesota Committee on Uniform Traffic Control Devices to require that all cities and counties put up the signs on the mast arms — just like the state does, she said. It is currently optional for cities and counties.

At the same time, she is lobbying federal officials to mandate that signs be required wherever the arrows are installed.

“Really, I think the root of the problem is that when the federal government came out with these signals, they did not mandate signs,” she said. “Each state can do whatever they want, which leads to chaos, of course.”

In September 2015, a 15-year-old Eagan teen died eight days after he was injured in a car crash that happened at an intersection with a flashing yellow arrow.

Aryan Mathur, a junior at Eagan High School, was a passenger in a car driven by a 16-year-old who failed to yield the right of way when turning his car west onto Wescott Road from northbound Lexington Avenue on Sept. 14. Their car was struck by a southbound pickup truck.

Tregilgas wonders if the accident could have been avoided had a sign saying “Left turn yield on flashing yellow arrow” been installed at the intersection; Dakota County does not install the signs.

“If a car is coming, you have to know that you have to yield to the oncoming traffic,” said Tregilgas, 55. “The reason for the signs is that it is not intuitive to know what to do at these signals, especially when you didn’t grow up with them. … I’m concerned about my safety, as well as that of my family and my community.”