Conspicuity Enhancement

The purpose of enhancing conspicuity for pedestrians is to increase the opportunity for drivers to see and avoid pedestrians, particularly when it is dark, since this is when 77% of pedestrian fatalities occur nationally (NCSA, 2023c). A conspicuous object is one that is not only visible but that stands out from the surrounding environment and commands attention. Rogé (2017) proposed that conspicuity can be sensory or cognitive. Sensory conspicuity is the ability to detect and distinguish an object in the landscape. Cognitive conspicuity relates to the whether the object is expected to be in the environment and can be seen and simultaneously understood.

A review of research about visual factors relevant to pedestrian-motorist crashes found that the challenges motorists face in detecting pedestrians include changes in vision during twilight hours and at night, headlamp glare, and age-related decline in visual function (Tyrrell et al., 2016). Motorists underestimate their visual limitations and often do not adjust their speed appropriately. Pedestrians also tend to overestimate their own visibility, wrongly assuming if they can see vehicles, vehicles must see them (Karsch et al., 2012). Research has demonstrated that conspicuity is greatly enhanced at night when pedestrians are in motion and use retroreflective clothing, especially on their extremities, but no studies have linked the use of the visibility aids to a decrease in crashes (Kwan & Mapstone, 2006). It is important to note that conspicuity enhancement is unlikely to overcome risky behaviors like motorist distraction (Szubski et al., 2019).

Retroreflective materials (materials that reflect light such as from car headlights back toward the source) are built into many shoes, including children’s and athletic shoes. Other accessories, such as arm or leg bands, gloves, vests, and caps are available from sporting goods stores and other vendors. Light sources, including strobes and other flashing lights, are also available. Many have been designed for bicyclists but are applicable to pedestrians. The difficulty with these devices is that the user must decide in advance to take and use them. See bicyclist conspicuity measures for more information. Bright colored and fluorescent clothing may also help to improve daytime conspicuity for pedestrians in some environments, but most research has focused on bicyclists and there may be differences in effectiveness for these groups.

Educational efforts could include a focus on being visible at night and in the daytime and making use of the conspicuity aids described in this section. Devices designed to be semi-permanently fastened to children’s clothing can be provided to parents through schools, group activities, or health care providers. Light sticks and reflective bands can be supplied with new cars or distributed by automobile clubs or insurance companies for use during vehicle breakdowns.

Use:

Retroreflective materials are used regularly in athletic-type shoes, occasionally in backpacks and jackets, and minimally in other clothing.

Effectiveness:

Widespread use of retroreflective materials would increase the ability of drivers to detect pedestrians at night in time to avoid crashes. Pedestrians wearing good retroreflective materials, particularly materials that highlight a person’s shape and moving extremities (i.e., wrists and ankles), or widespread use of active (flashing) lights can be detected hundreds of feet farther than can pedestrians in normal clothing, even with low-beam illumination (Koo & Huang, 2015; Karsch et al., 2012; Zegeer et al., 2004). A study in a controlled (closed road) environment also validated that pedestrians are detected more readily when they wear reflective elements on their moving body parts rather than attached to the torso (Tyrrell et al., 2009).

Adding electroluminescent (EL) garments to other retroreflective clothing also improves pedestrian conspicuity at night. EL garments are patches that produce light on their own that can be attached to clothing. They are visible regardless of angle and do not require another source of light to be visible in the dark. A nighttime on-road evaluation found that the addition of EL garments resulted in motorists reacting sooner to pedestrians farther outside the vehicle’s headlight light beam (Fekety et al., 2016). Increasing pedestrian's visibility with retroreflective and EL garments provided the greatest benefits to pedestrians in situations when vehicles are approaching pedestrians from a curve or when vehicles’ headlights are turned off.

Cost:

The cost to provide retroreflective materials is low if such supplementary materials are distributed in quantity and added to existing programs. Such items as reflective wrist and ankle bands are available commercially. To develop new programs promoting use of conspicuity materials would require more planning and start-up time and costs would also depend on communications strategies.

Time to implement:

Promoting increased conspicuity may require development of targeted messages and a publicity strategy.