Age impacts drivers’ reaction time to signage

August 12, 2015 | 0 Comments

Stereotypes abound when it comes to the age of drivers: young drivers are inexperienced and careless, while old drivers lack reflexes. But there are very real implications for age and at least one factor relating to road safety: reaction time when reading road signage. Does age impact whether a driver understands a road sign, and how long it takes them to do so? Researchers Tamar Ben-Bassat and David Shinar endeavored to figure out just that in their recently released study, “The effect of context and drivers’ age on highway traffic signs comprehension.”

Elder drivers

A study shows that reaction time to street signs slows down as we age. Researchers suggest interventions that will help safety. Image from Nicolas Alejandro Street Photography.

Sign comprehension is integral to road safety. (Case in point: Have you happened driven upon any of these drivers’-nightmare puzzles before?) If drivers can’t understand a sign, how can they obey it? As the researchers put it, “Traffic signs are common and important means for controlling traffic and improving traffic safety… But road signs comprehension is not that obvious.” It’s so not “obvious” that the U.S. Department of Transportation “put an emphasis on human factors testing of road signs legibility distance and comprehension” during the sign design process.

Other studies have revealed that sign comprehension varies among different kinds of road signs, “with some signs even interpreted” as being “opposite to their intended meaning.” Design is a factor, as is the driver’s age, gender and education, but these human factors haven’t been well studied.

For the study, researchers targeted 100 participants from two age groups: 50 young participants (30 males and 20 females) ranging in age from 23 to 30 years, and 50 older participants (30 males and 20 females) aged 65–91 years. (The young participants were undergrads at Ben-Gurion University of the Negev, and the older participants were a sample of active drivers from several retirement communities in Israel). The researchers presented 28 road signs, to young and older drivers in context and without it, and tested the impact of drivers’ age and sign context on how accurately they understood the signs. They also tested how much time it took them to respond.

The results? Younger drivers performed significantly better than older drivers on both of the tests. While context had no impact on either group’s comprehension, it did increase response time. Four key recommendations from the researchers include:

  • It’s better to post signs against a plain, white background, “as it avoids possible confounding effects due to location-specific surroundings”;
  • A “test of traffic signs’ meanings should be considered as part of a relicensing process for drivers older than 65, to verify that they are familiar with new signs and to refresh their memory on signs’ meanings in general”;
  • Consider if periodic training and “re-familiarization with signs” among older people to reduce extended comprehension times that are typical with older age;
  • Use standardized road signs to be “compatible with drivers’ associations and expectations. If changing a symbol is impractical, “such as when it is already consistent with the international code, it is advisable to add text above or below the symbol.”

To learn more, read the full study.

Category: Transportation

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