Be Seen After Dark—What Clothes Keep You Safe?

In 2014, 4,884 pedestrians died in car crashes in the United States and 65,000 more were injured. In other words, on average, 13 pedestrian die in America in a traffic accident every day —that is about 1 every 2 hours! For injuries, it is one pedestrian every 8 minutes, which is about 180 per day, as shown in Figure 1.

Figure 1. Drawing illustrating pedestrian injury and fatality statistics obtained from the 2014 Traffic Safety Factsheet listed in the Bibliography.

It is important to note that these accidents did not happen regularly all throughout the day. Figure 2 reveals that more than 3 out of every 4 pedestrian fatalitiesoccurred in poor light conditions, like dawn, dusk, or at night. Compare this to the distribution of fatalities for cyclists, which is about an even number of fatalities occurring during dark and during daylight conditions.

Figure 2. Pie charts illustrating the percentage of pedestrian and cyclist fatalities that happen during different light conditions. Data retrieved from 2014 Traffic Safety Factsheets listed in the Bibliography.

This raises questions, such as why are pedestrians so vulnerable during poor light conditions? What can a pedestrian do to be better seen?

You probably know that camouflage makes you disappear in the background, but would "not being camouflaged," as shown in Figure 3, be enough to be more visible at night?

Figure 3. Wearing garments that stand out with respect to the background (positive contrast), increase the chances of being seen compared to wearing garments that blend in with the background (negative contrast).

Humans "see" objects because light that reflects off an object reaches our eye. At night, there is very little light, so it is hard for us to see objects. Would some colors help get more light into our eyes, so we could see them better? Materials with bright colors bounce off more light than dark-colored objects do. Fluorescentobjects send out visible light when high-energy light shines onto them, and retro-reflective material—often referred to as reflective material— bounces back all the light that shines onto it. Figure 4 shows materials in these three "colors" in ample light conditions. Which one do you think will increase visibility the most in poor light conditions?