The overarching goal of this interdisciplinary research project was to advance our understanding of developmental changes in perceptual-motor functioning during childhood and early adolescence in the context of a problem with significant real-world implications. Specifically, this project used virtual reality technology to safely and systematically examine the development of pedestrian and cyclist road-crossing skills across childhood and early adolescence. The basic task involved repeatedly crossing a single lane of virtual traffic in an immersive bicycling or pedestrian simulator without colliding with a vehicle (Figure 1). The traffic travelled at a typical residential speed of 25mph and included both crossable and uncrossable gaps. We measured the size of the gaps chosen for crossing and the timing of movement (i.e., how closely youth cut in behind the lead car in the gap and how much time to spare they had when they exited the roadway). 

Our first set of findings focuses on how children?s skill as pedestrians and bicyclists develops during childhood and early adolescence. A major finding from our study of road-crossing performance in 6-, 8-, 10-, 12-, and 14-year-old and adult pedestrians was that children did not show adult-like pedestrian road-crossing skills until age 14. Priorto age 12, children?s gap choices were more risky and less discriminating than those of older children and adults. We also observed steady improvement in children?s timing of entry relative to the lead car in the gap up to age 14. Coupled with their less precise timing of entry, 6-, 8-, and 10-year-olds? gap choices resulted in significantly less time to spare and more collisions than 14-year-olds and adults. This prolonged developmental course in road-crossing skills may be particularly important for explaining continued risk for pedestrian injuries in early adolescence, especially in challenging situations such as high-density traffic.

A major finding from our study comparing how 8-, 10-, 12-, and 14-year-olds cross roads on foot vs. on bike is that the ability to coordinate gap decisions and crossing movements develops earlier for walking than for bicycling across roads with continuous traffic. Even though the traffic was exactly the same across the two tasks, younger children were better able to choose gaps and time their movement when they crossed the road as a pedestrian than as a bicyclist. Younger children?s difficulties with timing their movement in particular resulted in 8-, 10-, and 12-year-old bicyclists having significantly less time to spare when they exited the roadway than the 14-year-old bicyclists. Only 8-year-old pedestrians had less time to spare than 14-year-old pedestrians. Together, these findings suggest that transfer of skill from walking to bicycling is not complete. Rather, some amount of re-learning is necessary when children begin to cross roads as bicyclists.

Our second set of findings focuses on how two people cross roads together. One question we asked was how does crossing roads with friends impact risk taking in young adolescents and adults? Twelve-year-olds and adults either crossed our virtual roadway with a friend or alone. We found that pairs of adolescent friends exhibited more risky road-crossing behavior than pairs of adult friends. Adult pairs were more discriminating in their gap choices than adult solo crossers, crossing fewer of the smaller gaps and more of the larger gaps. This pattern did not hold for 12-year-old pairs compared to 12-year-old solo crossers. To compensate for their less discriminating gap choices, pairs of 12-year-olds adjusted their movement timing by entering and crossing the road more quickly. Given that young adolescents often cross roads together in everyday life, peer influences may pose a significant risk to road safety in early adolescence.

Another question we addressed was how parents and their 6-, 8-, 10-, and 12-year-old children cross roads together. We were especially interested in how parents attempted to guide children of different ages in the road-crossing task. We found that parents suggested more gaps for crossing with the younger than older children, and parents were more likely than children to communicate about the chosen gap prior to its arrival (e.g., ?let?s take the next one?), particularly at the younger ages. Overall, greater use of this anticipatory gap selection strategy by parents predicted safer road-crossing behavior in children, including more precisely timing their entry into the roadway and having more time to spare when exiting the roadway. By suggesting gaps prior to their arrival, parents may be helping children learn how to get ready to move at the right time, a critical skill for many everyday activities.

In sum, this interdisciplinary research project has yielded new insights into basic developmental changes in perceptual-motor skills across childhood and early adolescence, and provided a better understanding of the risk factors for injuries and fatalities involving child pedestrians and bicyclists. This research also lays the groundwork for interventions designed to teach parents how to promote safe road-crossing in children.

Last Modified: 05/03/2019
Modified by: Jodie M Plumert