As a driver, there is hardly anything scarier than narrowly missing a pedestrian who obviously thought you can see them as well as they can see your car. These dark figures seem to appear out of nowhere and move about erratically – as far as the driver is concerned.
According to some estimates, fatal accidents involving pedestrians are 3-7 times[1] more likely to occur when the lighting conditions are low. What, then, makes it so difficult for drivers to notice pedestrians even with vehicle headlights on?
1. The Attributes of the Human Vision
Broadly speaking, people have two types of vision: focal and ambient. Focal vision tells us “what is there” while ambient vision tells us “where we are”. Focal vision, which is used for detecting and recognizing objects, such as pedestrians, declines rapidly in dim light. Ambient vision is not greatly impaired when light level declines. Drivers can steer the car just as well at night as during the day and feel little need to slow, but inadvertently do not realize that their ability to see pedestrians has been greatly reduced.
Interestingly enough, many people with impaired vision (who are unable to receive a driver’s license due to their disability) still have vision superior to that of a normal person at night.
2. Drivers’ Attention and Where It Is Directed
Pedestrians usually appear on the side of the road, in the peripheral sector of vision. The driver is usually looking directly ahead. The pedestrian is hard to detect because people are much poorer at seeing objects off the direct line-of-sight.
3. Drivers’ Expectations
The maximum distance lit by vehicle low beams used in city driving is normally 150 feet (50 meters). Generally, unalerted drivers will seldom see a pedestrian at distances much greater than 100 feet (35 meters), which at regular city speeds of about 30 mph or 50 km/h roughly equals the distance it takes to stop the vehicle.
Three quarters of the pedestrians killed in road accidents are hit outside of crosswalks, probably because drivers do not expect them there.
4. Pedestrian Behavior
Pedestrians often inadvertently help to make themselves invisible by:
- Preferring to wear dark clothing.
- Assuming that they are as visible to the driver as a car with headlights is to them.
Another great risk factor is being under the influence of alcohol or drugs.
Simple Measures You Can Take to Maximize Your Safety As a Pedestrian
and Help to Be Seen Better By Drivers:
Wear light colored or bright clothing or accessories – these help to make you visible from a greater distance.
Be careful and use common sense:
- Walk on the side of the road
- Walk facing oncoming traffic if there is no sidewalk
- Pay attention to approaching vehicles and stay out of their way
When you have to cross a street in the dark, preferably choose a place under a street light. In many European countries and in Canada, pedestrian crossings are supplemented by a street light, which casts light onto the crosswalk – this makes a huge difference in drawing drivers’ attention to the fact that pedestrians may be on the move, and also helps greatly with discernibility of the pedestrian. Your best bet in places where there are no such crossings is to try and mimic the conditions as closely as possible.
A lit crosswalk in Burnaby, British Columbia (via Wikipedia)
And finally, wear a reflector.
Get one at http://www.visibelreflective.com
[1] http://www.ncbi.nlm.nih.gov/pubmed/12067111
Parts of this article have been compiled based on materials published by Marc Green, PhD