Winter 2006 -- Vol. 59, No. 1

No matter how much engineers and manufacturers work to make automobiles safer, there’s one part they can’t control — as my mother used to say — “the loose nut behind the wheel.”

Of course, she was referring to “the other driver,” not herself. Truth is many of us tend to think we drive better than we actually do.

In an effort to increase driver and pedestrian safety, Clemson’s psychology department has been conducting a series of research projects that explore road users’ capabilities and limitations. Their goal is to achieve a better understanding of drivers so that transportation systems will be designed accordingly.

Researchers include psychology faculty Johnell Brooks, Rick Tyrrell, Fred Switzer and Lee Gugerty, assisted by graduate and undergraduate students. They’re joined this year by a national leader in transportation research, Fred Owens, who is on sabbatical from Franklin & Marshall College in Pennsylvania to work at Clemson.

Their research ranges from cell phones to new dashboard displays to night driving and pedestrian safety. Much of their work takes place within a driving simulator. The simulator facility, housed on the third floor of Brackett Hall, has a full car, eight networked computers and surrounding projection screens.

Matters of age

Alumna Johnell Brooks ’98, M ’02, Ph.D. ’05 has been involved in transportation research with university and high school students, roadway workers and senior citizens in the United States and Australia. In fact, the last three years of her doctoral work was funded by a prestigious Dwight D. Eisenhower Graduate Transportation Fellowship for more than $100,000 from the Department of Transportation. She’s the first Eisenhower Fellow in the state.

Her primary interest is investigating the relationship between how well drivers of different ages think they can see and drive in different visually challenging conditions as compared to how well they actually perform.

In a recent study, Brooks asked drivers who ranged in age from 18 to 80 to drive the simulator. Participants did their best to stay in their lane while driving at a moderately high speed on an unusually curvy road as Brooks manipulated the light conditions. Before driving, participants had estimated how well they thought they would be able to see and steer in the different conditions.

“Although drivers were surprised by their ability to stay within their lane in the dimmest lighting conditions,” says Brooks, “the older drivers overestimated their ability to see, and both university students and middle-age adults underestimated their ability to see. None appeared to appreciate that the visual skills needed for steering are different from those that allow us to see objects.”

This research has implications for drivers, pedestrians and roadway designers, whose knowledge of selective degradation could result in increased nighttime safety.

Night vision

She and fellow researcher Rick Tyrrell are also collecting data on steering accuracy in challenging conditions such as increased levels of blur and reduced visual fields in addition to different levels of fog.

Tyrrell, who has studied night vision for more than 20 years, is focusing on drivers’ ability to see pedestrians at night. He completed a study on a closed-road test track in Australia to determine the effects of driver age on ability to see pedestrians in different clothing conditions. His studies aim to answer two questions: What are the safety implications of drivers’ not being able to see well at night? And why are people not aware of this problem?

“Although nobody sees well at night, few people realize just how impaired their night vision is,” says Tyrrell. “Because we find it so easy to steer our vehicles, we get fooled into thinking we can see everything we need to see. But we might be completely unaware of the jogger who is right in front of us.”

Much of the focus is on the pedestrians themselves — including trying to convince pedestrians that they are not as visible at night as they think. Tyrrell and Brooks are collecting related data from S.C. Department of Transportation workers. These “professional pedestrians” are at particularly high risk at night. This spring, they’ll concentrate on Spanish-speaking roadway workers.

Tyrrell is also leading a Michelin-funded study of drivers’ reactions to the automated tire pressure monitoring systems that will soon be standard in all new vehicles.

Risky business

Fred Switzer’s research examines drivers’ response to risks. He looks at how much drivers notice when driving conditions are worsening — heavier traffic, settling fog, roadway construction — and how they react if they do notice.

His team designed a novel dashboard display — a small computer screen similar to in-car navigation systems. The test simulates a situation in which the driver comes up on a car in the fog. The display shows the leading car, even when it’s still out of visibility range.

“We found that people fall into two groups: followers and laggers,” says Switzer. “Followers keep you in sight no matter how fast you’re going or how close they have to follow. Laggers fall back until they can’t see you through the fog.”

Last summer Switzer’s team did a study involving a number of other risks, such as nondivided vs. divided highways. His findings showed that, unless drivers are cued in some way to pay attention, most miss the subtle increases and decreases in environmental risks while they’re driving.

Lee Gugerty’s research includes the effects of drivers using cell phones. His team compared how different kinds of verbal interaction — with a fellow passenger or on a cell phone — affected driving spatial tasks and drivers’ awareness of the road situation. His team is also studying drivers with Attention Deficit and Hyperactivity Disorder.

He and Brooks have examined how people make navigational decisions. Much of their research is based on a task needed to operate unmanned aerial vehicles. Their studies investigated the types of strategies that novice and experienced navigators use to make cardinal direction judgments. While these judgments are important and necessary in navigation, people in general aren’t very good at this task.

By understanding strengths and limitations of the human factor, Clemson psychology professors are working to make us all better and safer drivers. For more information or to become a participant, call Johnell Brooks at (864) 656-1703.