Deciding when to cross in front of an autonomous vehicle: How child and adult pedestrians respond to eHMI timing and vehicle kinematics.

How autonomous vehicles (AVs) communicate their intentions to vulnerable road users (e.g., pedestrians) is a concern given the rapid growth and adoption of this technology.

How do bicyclists respond to vehicles with adaptive headlamp systems? A nighttime study in an immersive virtual environment.

Introduction: The risk of motor vehicle-bicyclist crashes and fatalities is greater during nighttime than daytime lighting conditions, even though there are fewer cyclists on roadways at night. Vehicle Adaptive Headlamp Systems (AHS) aim to increase the visibility of bicyclists for drivers by directing a spotlight to illuminate bicyclists on or near the roadway. AHS technology also serves to alert bicyclists to the approaching vehicle by illuminating the road beneath the rider and by projecting a warning icon on the roadway.

Should I stay or should I go? The cerebral bases of street-crossing decision.

An observer willing to cross a street must first estimate if the approaching cars offer enough time to safely complete the task. The brain areas supporting this perception, known as Time-To-Contact (TTC) perception, have been mainly studied through noninvasive correlational approaches. We carried out an experiment in which patients were tested during an awake brain surgery electrostimulation mapping to examine the causal implication of various brain areas in the street-crossing decision process.

Longitudinal and Concurrent Effortful Control as Predictors of Risky Bicycling in Adolescence: Moderating Effects of Age and Gender.

Objective: Collisions between bicycles and motor vehicles are one of the leading risk factors for injury and death in childhood and adolescence. We examined longitudinal and concurrent effortful control (EC) as predictors of risky bicycling behavior in early- to mid-adolescence, with age and gender as moderators. We also examined whether EC was associated with parent-reported real-world bicycling behavior and all lifetime unintentional injuries.

How children judge affordances when walking and bicycling across virtual roads: Does mode of locomotion matter?

This investigation examined whether the mode of locomotion matters in how 8-, 10-, 12-, and 14-year-old children ( = 91) judge dynamic affordances in a complex perception-action task with significant safety risks. The primarily European American children in the sample came from the area of Iowa City, Iowa and were balanced for gender. The same children crossed a single lane of continuous traffic on foot and on bike (order counterbalanced) in identical immersive virtual environments.

Do Simulated Augmented Reality Overlays Influence Street-Crossing Decisions for Non-Mobility-Impaired Older and Younger Adult Pedestrians?

Objective: This study used a virtual environment to examine how older and younger pedestrians responded to simulated augmented reality (AR) overlays that indicated the crossability of gaps in a continuous stream of traffic.

Background: Older adults represent a vulnerable group of pedestrians. AR has the potential to make the task of street-crossing safer and easier for older adults.

A comparison of daytime and nighttime pedestrian road-crossing behavior using an immersive virtual environment.

Objective: Reduced visibility for both drivers and pedestrians is a key factor underlying the higher risk of vehicle-pedestrian collisions in dark conditions. This study investigated the extent to which pedestrians adjust for the higher risk of road crossing at night by comparing daytime and nighttime pedestrian road crossing using an immersive virtual environment.

Method: Participants physically crossed a single lane of continuous traffic in an immersive pedestrian simulator.

How Do Child ADHD Symptoms and Oppositionality Impact Parent-Child Interactions When Crossing Virtual Roads?

Objective: This study examined how parents and children interact when crossing virtual roads together. We examined (1) whether children's inattention/hyperactivity and oppositionality and children's failure to jointly perform the task interfered with parents' efforts to scaffold children's road-crossing skill and (2) whether experience with the joint road-crossing task impacted children's subsequent performance in a solo road-crossing task.

Methods: Fifty-five 8- to 10-year-old children with and without attention-deficit/hyperactivity disorder and their parents first jointly crossed a lane of traffic in an immersive pedestrian simulator.

Do Inattention/Hyperactivity and Motor Timing Predict Children's Virtual Road-Crossing Performance?

Objective: The goal of this investigation was to examine how individual variation in inattention and hyperactivity is related to motor timing difficulties and whether children's performance on simple laboratory timing tasks is related to their performance on a virtual road-crossing task using a head-mounted virtual reality display system.

Methods: Participants were a community sample of 92 9- to 11-year-old children. Parents completed questionnaires assessing their child's inattention and hyperactivity.

How do pedestrians respond to adaptive headlamp systems in vehicles? A road-crossing study in an immersive virtual environment.

Three-fourths of pedestrian fatalities in the U.S. occur in the dark (National Center for Statistics and Analysis, 2020).

Let's Cross the Next One: Parental Scaffolding of Prospective Control Over Movement.

This investigation examined parental scaffolding of children's prospective control over decisions and actions during a joint perception-action task. Parents and their 6-, 8-, 10-, and 12-year-old children (N = 128) repeatedly crossed a virtual roadway together. Guidance and control shifted from the parent to the child with increases in child age.

How Does Crossing Roads with Friends Impact Risk Taking in Young Adolescents and Adults?

Objective: The goal of this investigation was to examine how crossing roads with a friend versus alone affects gap decisions and movement timing in young adolescents and adults.

Methods: Ninety-six 12-year-olds and adults physically crossed a single lane of continuous traffic in an immersive pedestrian simulator. Participants completed 30 crossings either with a friend or alone.

Joint Action in a Virtual Environment: Crossing Roads with Risky vs. Safe Human and Agent Partners.

This paper examines how people jointly coordinate their decisions and actions with risky vs. safe human and agent road-crossing partners (Fig. 1 ).

Timing Is Almost Everything: How Children Perceive and Act on Dynamic Affordances.

A key challenge for the developing perception-action system is learning how to move the self in relation to other moving objects. This often involves perceiving and acting on affordances or possibilities for action that depend on the relation between the characteristics of the individual and the properties of the environment (Gibson, 1979). This chapter overviews our program of research on perceiving and acting on dynamic affordances (i.

Harnessing Vehicle-to-Pedestrian (V2P) Communication Technology: Sending Traffic Warnings to Texting Pedestrians.

Objective: We examined how sending mobile-device warnings to texting pedestrians when they initiate an unsafe road crossing influences their decisions and actions.

Background: Pedestrian texting has been identified as a key risk factor in pedestrian-vehicle collisions. Advances in sensing and communications technology offer the possibility of providing pedestrians with information about traffic conditions to assist them in safely crossing traffic-filled roadways.

Changes in perception-action tuning over long time scales: How children and adults perceive and act on dynamic affordances when crossing roads.

This investigation examined developmental change in how children perceive and act on dynamic affordances when crossing roads on foot. Six- to 14-year-olds and adults crossed roads with continuous cross-traffic in a large-screen, immersive pedestrian simulator. We observed change both in children's gap choices and in their ability to precisely synchronize their movement with the opening of a gap.

Optimal Camera Placement for Motion Capture Systems.

Optical motion capture is based on estimating the three-dimensional positions of markers by triangulation from multiple cameras. Successful performance depends on points being visible from at least two cameras and on the accuracy of the triangulation. Triangulation accuracy is strongly related to the positions and orientations of the cameras.

Risky bicycling behavior among youth with and without attention-deficit hyperactivity disorder.

Background: Injury risk from car-bicycle collisions is particularly high among youth with attention-deficit hyperactivity disorder (ADHD). Here, we capitalized on advances in virtual environment technology to safely and systematically examine road-crossing behavior among child cyclists with and without ADHD.

Methods: Sixty-three youth (26 with ADHD, 37 non-ADHD controls) ages 10-14 years crossed 12 intersections with continuous cross-traffic while riding a high-fidelity bicycling simulator.

How Do Children Perceive and Act on Dynamic Affordances in Crossing Traffic-Filled Roads?

Successfully perceiving and acting on dynamic affordances is critical for children and adults to function. In our work, we look at how children cross roads as a model for understanding how they learn to perceive and act on dynamic affordances. Ten- to 14-year-old children and adults ride an interactive bicycling simulator through an immersive virtual environment where they cross intersections with continuous cross traffic.

Linking Decisions and Actions in Dynamic Environments: How Child and Adult Cyclists Cross Roads With Traffic.

Unlike affordances involving stationary objects, affordances involving moving objects change over time. This means that actions must be tightly linked to decisions, making perceiving and acting on affordances involving moving objects challenging for children and adults alike. Here, we overview our program of research on how children and adults perceive and act on moving objects in the context of bicycling across roads in an immersive virtual environment.

Dynamic affordances in embodied interactive systems: the role of display and mode of locomotion.

We investigated how the properties of interactive virtual reality systems affect user behavior in full-body embodied interactions. Our experiment compared four interactive virtual reality systems using different display types (CAVE vs. HMD) and modes of locomotion (walking vs.

How children and adults learn to intercept moving gaps.

We used an immersive virtual environment to examine how children and adults learn to intercept moving gaps and whether children and adults benefit from variability of practice. Children (10- and 12-year-olds) and adults attempted to bicycle between two moving vehicle-size blocks without stopping. In Experiment 1, block motions were timed such that if participants maintained a constant speed, they would intercept the gap between the blocks.

Manipulating perception versus action in recalibration tasks.

We conducted six experiments to examine how manipulating perception versus action affects perception-action recalibration in real and imagined blindfolded walking tasks. Participants first performed a distance estimation task (pretest) and then walked through an immersive virtual environment on a treadmill for 10 min. Participants then repeated the distance estimation task (posttest), the results of which were compared with their pretest performance.

Preadolescent temperament and risky behavior: bicycling across traffic-filled intersections in a virtual environment.

Objective: This investigation used a bicycling simulator to examine how preadolescent temperament is related to risky behavior.

Methods: Children aged 10 and 12 years (N = 109) rode a bicycle through a virtual environment where they crossed intersections with continuous cross traffic. Mothers filled out the Early Adolescent Temperament Questionnaire-Revised.

Perceiving and acting on complex affordances: how children and adults bicycle across two lanes of opposing traffic.

This investigation examined how children and adults negotiate a challenging perceptual-motor problem with significant real-world implications--bicycling across two lanes of opposing traffic. Twelve- and 14-year-olds and adults rode a bicycling simulator through an immersive virtual environment. Participants crossed intersections with continuous cross traffic coming from opposing directions.