New BYU Study Shows Dynamic Road Signs May Reduce Accidents

Contributed By Ryan Morgenegg, Church News staff writer

  • 26 March 2015

Drivers react an average of 50 milliseconds faster to more dynamic signs. These three signs demonstrate from left to right more and more dynamism.

Article Highlights

  • A joint study with BYU and University of Michigan researchers shows that dynamic road signs may reduce accidents.

A report released in February by the U.S. Department of Transportation asserts that 95 percent of the time, the critical reason for automobile crashes is related to the driver.

While on the road, automobile drivers must continually make split-second decisions. Sometimes milliseconds make all of the difference in preventing a casualty, and a few feet could mean the difference between life and death.

Researchers Ryan Elder from BYU and Luca Cian and Aradhna Krishna from the University of Michigan have discovered a way to give a little extra time to drivers when it comes to near accidents.

A new study recently published in the Journal of Consumer Research finds that drivers react significantly faster in driving situations to roadside signs when those signs depict increased movement.

“A sign that evokes more perceived movement increases the observer’s perception of risk, which in turn brings about earlier attention and earlier stopping,” the study authors said in the Journal of Consumer Research. “If you want to grab attention, you need signs that are more dynamic.”

According to the Centers for Disease Control and Prevention, in 2012, 4,743 pedestrians were killed in traffic crashes in the United States, and another 76,000 pedestrians were injured. That means there is one crash-related pedestrian death every 2 hours, and a pedestrian injury occurs every 7 minutes. Pedestrians are 1.5 times more likely than passenger vehicle occupants to be killed in a car crash on each trip.

The study results show dynamic signs are road signs that depict images with greater movement and energy, appearing to move at a higher speed. For example, the photo included with this story shows three school crossing signs. The sign on the left from the U.S. has low dynamism. The sign from Poland in the middle has an increased level of dynamism. The sign on the far right is the one of greatest interest according to the study because it is highly dynamic. The lively figures on the sign appear to be sprinting.

“If the figures look like they’re walking, then your brain doesn’t worry about them shooting out into the road,” the researchers said in the Journal of Consumer Research. “But if they’re running, then you can imagine them being in front of your car in a hurry.”

Taking things a step further, the authors of the study explored how static and dynamic imagery can impact actual behavior. Using a variety of means such as driving simulations, click-data heat maps, surveys, reaction time exercises, and eye-tracking, the researchers found that signs conveying a higher perception of movement lead to quicker reaction time from observers.

Applying the research to actual road events, the study found that participants analyzed in a driving simulation reacted an average of 50 milliseconds faster to dynamic road signs. That means a car traveling 60 mph that needed to stop would travel 4.4 feet less with an extra 50 milliseconds to react and slow a vehicle. That extra time and distance can mean the difference between a fatality and a near miss.

Another experiment performed by the team involved using eye-tracking technology to measure how long it takes a person’s eyes to notice a traffic sign. The eye-tracker results showed that signs with higher perceived movement (dynamic) attracted (and maintained) significantly earlier attention than static signs.

“Things that look like they’re going to move get moved in our minds,” the authors said. “Our minds want to continue the motion that is contained within an image—and that has important consequences.”

With more than 37,000 people killed every year in the U.S. due to car accidents and another 2.35 million injured or disabled, Luca Cian, Aradhna Krishna, and Ryan Elder hope the study will ultimately influence governmental policy leading to changes that will reduce accident-related injuries and deaths.

In the actual article published in the Journal of Consumer Research, the researchers wrote about additional benefits as well, stating: “Since variations in traffic iconography systematically resulted in safer behavior, this research could impact accident-related injuries and even mortality rates from traffic accidents. Secondary effects would be seen with reductions in automobile repair expenses, as well as car insurance health care costs.”