Decreasing Traffic Fatalities through Psychology
When he’s not teaching upper-level psychology courses on how environmental stimuli influence human perception, decision making and motor control, Brian Dyre drives up and down Alaska’s rural Seward Highway. It runs south from Anchorage through the nearly 7 million-acre Chugach National Forest to the Kenai Peninsula, which juts into the Gulf of Alaska.
It’s a rugged and picturesque trip, and one that Dyre travels virtually, using a simulator to research how drivers respond to visual information along rural roadways in an attempt to reduce accidents.
As an associate professor of psychology and communication studies, Dyre works with the National Institute for Advanced Transportation Technology (NIATT) in the University of Idaho College of Engineering, which was commissioned by the Alaska Department of Transportation (ADOT) in 2013 to research strategies for improving the safety of the passing lanes that the state spent millions of dollars to construct, but which led to horrific head-on collisions. In applying psychophysics, Dyre and his team found a solution that will potentially save countless lives — and is currently awaiting approval from the federal government.
Rather than field testing strategies for improving the safety of passing lanes — which in many cases would prove unsafe, costly and bureaucratically impossible — Dyre used a driving simulator that he built with colleague Steffen Werner in 2008. In a video game-like scenario, the simulator allows participants to sit in the cab of a truck and navigate a computerized roadway. Using this setup, Dyre then studied how drivers responded to the surrounding environment and various inputs, such as road signs and highway markings.
“One of the biggest implications is seeing the human being as part of an environment,” Dyre said. “You’re sending signals to the human being and comparing the output and input to figure out what’s going on in their brain.”
Dyre, along with NIATT Director Ahmed Abdel-Rahim and a crew of students, tested 10 strategies for increasing the safety of Alaska’s passing lanes. They posted signs suggesting that drivers being passed slow down; lowered the speed limit in the right-hand lane, while maintaining a higher speed limit in the passing lane; and created speed illusions by increasing the highway’s edge rate, which involves painting roadside markings that get progressively closer together and give drivers a sense that they are moving faster than they are.
Dyre hypothesized that this increased edge rate would be the most successful scenario based on prior research. But, it only slowed down drivers by 1 mph — a meager result that wouldn’t convince the state to invest in new roadway markings. The split speed limit, however, led to a decrease in speed by 5-6 mph, which was the result Dyre and his team wanted.
Currently underway is another ADOT-commissioned project for which Dyre and assistant professor in civil and environmental engineering Kevin Chang are using the simulator to determine how certain line-of-sight obstacles, such as vegetation and guardrails, affect a person’s perception of safe passing conditions. He started by removing obstructions — essentially clearcutting vegetation in his virtual world — and will then add obstacles back in. The findings will help inform Alaska’s transportation department on decisions related to highway maintenance and may give insight into where to eliminate passing zones.
“There’s quite a bit of public resistance to taking passing zones away,” Dyre said. “So ADOT wants to have good, sound scientific basis for their decisions.”
Although Dyre has never been to Alaska in real life, he hopes to one day drive the sections of highways that he has tested. Pending approval of the mandates that he’s proposed to Alaska’s transportation sector, the highway that leads to the state’s most popular travel destinations may be a safer thoroughfare once he gets there.