Safety of blinking traffic signals overnight questioned

There's an old joke about the small town so dull that the only thing to do on a Friday night is watch the only traffic light switch to flashing red.

For David Schroeder, 46, of Cedar Rapids, flashing traffic signals are no joke. He'd like Cedar Rapids and other cities to stop programming signals to blink yellow on main thoroughfares and red on side streets.

“From my experience, it's an unbelievably stupid thing to do and completely unsafe for the people traveling through town,” said Schroeder.

Cities program signals to flash, usually in the pre-dawn hours with little traffic, to reduce unnecessary waits for motorists. The practice is used at a significant number of the 200 signalized intersections in Cedar Rapids, including many downtown and on the west side.

“We try to weigh the safety of operating them a certain way versus the efficiency of it,” said Leslie Hart, associate traffic engineer for Cedar Rapids.

On Sept. 15, 2007, Schroeder was driving his motorcycle home a little past midnight after having drinks with his girlfriend at Chappy's Safari Lounge. He was heading southwest on Williams Boulevard when his life virtually hit a wall.

Schroeder awoke from a coma a month later, unable to recognize his surroundings or explain what happened. He had a skull fracture, multiple fractures of his left leg, a broken nose and other injuries. When it became apparent Schroeder would live, he was cited for drunken driving.

Schroeder doesn't dispute that he'd been drinking, but he's confident his accident wasn't because of alcohol impairment. He limited his drinking when he was out on the motorcycle, Schroeder said.

According to the accident investigation, Schroeder was passing through a flashing yellow light at Williams Boulevard and Trent Street SW, when a vehicle pulled out from the flashing red signal on Trent Street. His motorcycle T-boned the vehicle, which left the scene. Another passing motorist found him and called authorities.

“To this day I'll always believe I would never have been injured so severely if the light had been functioning properly as it was designed to do,” Schroeder said.

Three weeks ago, Schroeder said, he witnessed a similar accident after midnight at Wiley and Williams boulevards SW.

“A woman pulled out from the flashing red light on Wiley from the south side of Williams and pulled out in front of a pickup truck going to the southwest on Williams (through a flashing yellow signal),” he said. “I was just a couple of cars behind her.”

Schroeder approached the woman driver.

“The first words out of her mouth were ‘I didn't realize they didn't have to stop,' ” he said.

Whether overnight blinking traffic lights are a good idea is being debated among traffic engineers, Hart said, although it's still a common practice.

“Nobody can really see the indication that is being shown to the driver on the other street,” Hart said. “If I'm facing the red, it's a little hard for me to confirm what the other person is seeing.”

Hart said Cedar Rapids examines accident records annually to determine whether they warrant eliminating the overnight blinker cycle.

Iowa City uses no overnight flashing traffic signals. Consistency is one of the issues, said Darian Nagle-Gamm, city traffic engineer.

“When you make traffic controls temporary, it can lead to misunderstandings,” Nagle-Gamm said.

Iowa City has more overnight traffic than Cedar Rapids, so it's important to keep the traffic lights cycling, Nagle-Gamm said. To prevent long waits, the city updates signal timing at least every five years to make sure the light patterns match traffic volume.

Coralville uses no overnight blinkers, either, said Scott Larson, assistant city engineer. Coralville's signals are equipped with sensors that tell the traffic signal's computer when a vehicle is waiting.

Cedar Rapids received funding from the state's Clean Air Attainment program to upgrade some traffic signals at 19 west-side intersections recently, Hart said. When the work is done, she expects the city to reprogram some of the lights - like the Westdale Mall access off Edgewood Road - from an overnight blinking cycle to a continuous cycle.

Scott Falb, a driver-safety specialist at the Iowa Department of Transportation, said he's not aware of any studies on the effects of overnight blinking traffic signals, but he could understand how drivers with the blinking red signal might think the cross-traffic also has to stop.

The 80 to 120 seconds some motorists have to wait for a light to change is a small price to pay for safety, Schroeder said.