'Element of surprise' explains why motorcycles are a greater traffic hazard than cars

January 27, 2014

"I didn't see it, because I wasn't expecting it there," might be the more accurate excuse for motorists who have just crashed into a bus or a motorcycle. The mere fact that such vehicles are less common than cars on our roads actually makes it harder for drivers to notice them, says Vanessa Beanland of The Australian National University. Beanland and colleagues conducted research at Monash University on how the so-called "low-prevalence effect" increases the likelihood of accidents. The study is published in Springer's journal Attention, Perception, & Psychophysics.

The impact that this low-prevalence effect has on a person's ability to search through static images, such as in airport luggage screening, has been the topic of previous research. However, Beanland's research team is the first to publish results on how it influences people's ability to safely perform dynamic tasks, such as driving.

They used a driving simulator experiment involving 40 adult drivers to investigate whether it is easier for drivers to detect and respond to specific types of vehicles when they occur more frequently in surrounding traffic. The drivers had to detect two types of vehicles: motorcycles and buses. The researchers varied how frequently these vehicles appeared. Half of the subjects were subjected to a high prevalence of motorcycles and a low number of buses, with the other half experiencing the reverse.

Although participants were explicitly instructed to search for both buses and motorcycles, the researchers found that the attention of the observers was biased toward whichever vehicle occurred more frequently during the simulated detection drive. This in turn affected the speed at which drivers were able to detect low-prevalence targets. In the simulated test in which motorcycles occurred more frequently, the car drivers were able to detect them on average from 51 meters farther away than in the tests where they occurred less often. In effect, at a driving speed of 60 km/h, this allowed the drivers an extra 3 seconds to respond. Similarly, drivers had an extra 4.4 seconds to react to buses in situations where they occurred more frequently.

The results suggest that drivers' inability to always notice motorcyclists is partially due to the fact that motorcycles occur relatively rarely on our roads, and that are simply not on the look-out for them. It therefore appears that by increasing the prevalence of a visual search target it is possible to effectively yet temporarily make it stand out better within a specific visual environment.

"Drivers have more difficulty detecting vehicles and hazards that are rare, compared to objects that they see frequently," says Beanland, who believes that the ability to accurately perform visual searches is crucial to ensuring safe driving and avoiding collisions.

Explore further: ADHD and texting found to significantly impair teenage driving

More information: Beanland, V. et al. (2014) Safety in numbers: Target prevalence affects the detection of vehicles during simulated driving, Attention, Perception, & Psychophysics. DOI: 10.3758/s13414-013-0603-1

Related Stories

ADHD and texting found to significantly impair teenage driving

August 12, 2013
ADHD and texting both significantly impair driving performance among teenagers, according to a study published online today in JAMA Pediatrics.

iPod use while driving is dangerously distracting

September 27, 2013
New road safety research suggests that scrolling through music selections on MP3 players while driving is just as distracting as text messaging or entering details into a navigation system.

Drivers education for older drivers remains for 2 years, HF/E researcher finds

April 26, 2013
In seeming contrast to the notion that the elderly often have memory problems, a new study from an HF/E researcher finds driver retraining to be an effective strategy for improving the safe-driving habits of older drivers ...

Recommended for you

Researchers crack the smile, describing three types by muscle movement

July 27, 2017
The smile may be the most common and flexible expression, used to reveal some emotions, cover others and manage social interactions that have kept communities secure and organized for millennia.

Even babies can tell who's the boss, UW research says

July 27, 2017
The charismatic colleague, the natural leader, the life of the party - all are personal qualities that adults recognize instinctively. These socially dominant types, according to repeated studies, also tend to accomplish ...

Ketamine for depression encouraging, but questions remain around long-term use

July 27, 2017
A world-first systematic review into the safety of ketamine as a treatment for depression, published in the prestigious Lancet Psychiatry, shows the risks of long-term ketamine treatment remain unclear.

DREAMers at greater risk for mental health distress

July 27, 2017
Immigrants who came to the United States illegally as small children and who meet the requirements of the Development Relief and Education for Alien Minors Act, more commonly known as DREAMers, are at risk for mental health ...

Negativity, be gone—new online tool can retrain your brain

July 27, 2017
Anxiety and depression can have devastating effects on people's lives. In some cases, the mental disorders lead to isolation, poverty and poor physical health, things that often cascade to future generations.

Research aims to shape more precise treatments for depression in women

July 27, 2017
Among women in the United States, depression is at epidemic levels: Approximately 12 million women in the U.S. experience clinical depression each year, and more than 12 percent of women can expect to experience depression ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.