Forensic Engineers and Consultants

Archive: Collisions

Why Pedestrians Overestimate Their Visibility: A Dive into the Psychology of Road Safety

When we step out onto the road as pedestrians, most of us assume that we are easily visible to oncoming drivers. However, research shows that pedestrians frequently overestimate their visibility, especially at night or in low-light conditions. This overconfidence can lead to dangerous situations, contributing to accidents and fatalities. Understanding why pedestrians overestimate their visibility is crucial for improving road safety and preventing accidents.

Pedestrians tend to believe that they are more visible to drivers than they actually are.

Because pedestrians can see the headlights of oncoming traffic and assume they are within the driver’s line of sight, they often mistakenly believe drivers can see them just as clearly. This bias may prevent pedestrians from considering the limitations of a driver’s view, such as blind spots, obstructions, or poor lighting conditions.

From the pedestrian’s point of view, vehicle headlights are extremely conspicuous. This may lead pedestrians to believe they are more visible to driver than they actually are.

In addition, pedestrians often assume that drivers are always alert and actively looking for pedestrians, particularly in areas with heavy foot traffic or near crosswalks. They might think drivers are always prepared to stop, even when the reality is that drivers may be distracted, focused on other traffic, or simply unable to see them in time.

Pedestrians might think that wearing light-colored or even dark clothing makes them sufficiently visible to drivers. However, research shows that at night or in low-light conditions, clothing without reflective materials is often not visible until it is too late. While light-colored clothing (like white or yellow) may offer slightly better visibility than dark clothing in low-light situations, it still falls far short of what is needed for drivers to see pedestrians from a safe distance. Research shows that pedestrians wearing light colors like white or yellow are not visible to drivers until they are dangerously close, especially at night. Dark clothing (such as black or navy) makes pedestrians nearly invisible to drivers at night. Dark clothed pedestrians blend into the background, making it extremely difficult for drivers to detect them in time to avoid an accident. Clothing with retroreflective material is far more effective in enhancing pedestrian visibility because the material reflects the light from vehicle headlights directly back to the driver. Research demonstrates that pedestrians wearing reflective vests, strips, or accessories are visible to drivers from much greater and safer distances.

Clothing with retroreflective material enhances pedestrian visibility at night.  Image credit Google Images.

The consequences of pedestrians overestimating their visibility can be severe. Thousands of pedestrians are injured or killed each year due to road accidents, with a significant number of these incidents occurring at night or in low-light conditions. Overconfidence leads pedestrians to take unnecessary risks, such as crossing roads without looking properly or assuming drivers will see them and yield.

Pedestrians overestimate their visibility due to biases, lack of awareness, and misconceptions about driver behavior. This overconfidence can lead to dangerous situations on the road. By understanding the psychological factors at play and taking proactive steps to increase visibility, both pedestrians and drivers can contribute to safer roads and fewer accidents. Road awareness is the first step toward reducing risks and improving both pedestrian and driver safety.

Ellen Szubski, Ph.D., CXLT, CPSI, AHFP, is a human factors consultant at The Warren Group. She earned a Doctorate of Philosophy in Human Factors Psychology and a Master of Science in Applied Psychology from Clemson University.  She did her dissertation on “The Influence of Pedestrian Biological Motion on Time-To-Collision Estimates at Night”.  She is also a Certified XL Tribometrist, Certified Playground Safety Inspector and a Certified Associate Human Factors Professional (AHFP). Prior to entering the forensic field, Ellen planned and conducted experiments for a major bicycle manufacturer. She also conducted laser strike perception studies for the Department of Defense.  Ellen applies her experience in Human Factors to the analysis of crash investigations and other personal injury matters. These matters often include collisions involving vulnerable road users and drivers, driver distraction, and slips, trips, and falls. She utilizes her knowledge of OSHA regulations, codes, and standards in her analysis of premises liability incidents and safety consulting.  Ellen is a current member of the Human Factors and Ergonomics Society (HFES) and it’s Forensic Professional Technical Group.

Author

Human Factors and Halloween Hazards: Trip and Falls

Author

Trick-or-treating is a fun and festive activity, but it comes with certain hazards that can pose risks to children and even adults. In addition to vehicle and pedestrian collisions and accidents, tripping and falling while trick-or-treating is a common hazard, especially for children navigating unfamiliar and dimly lit areas at night.

Children and adults can face tripping hazards on walkways while trick-or-treating.

Tripping hazards can be mitigated through compliance with walkway safety standards such as ASTM F 1637-2021: Standard Practice for Safe Walking Surfaces. ASTM F1637 is a standard that provides guidelines for the safe design, construction, and maintenance of pedestrian walkways to help prevent slip, trip, and fall incidents. In general, this standard emphasizes the importance of maintaining both interior and exterior walkways in a condition free of hazards such as protrusions, holes, and other tripping risks.

While trick or treating, elevation changes are a potential tripping hazard for children and adults. According to the safety standard ASTM F1637-21, vertical elevation changes up to ¼ inches are allowed in walkways. Vertical elevation changes between ¼ and ½ inches must have a beveled edge with a slope no greater than 1:2 (rise:run). Any vertical elevation changes greater than ½ must be transitioned by either a ramp or stairway that complies with applicable building codes, regulations, standards, or ordinances, or all of these.

Elevation changes on the sidewalk pose a tripping hazard for trick-or-treaters during Halloween.

In addition to elevation changes in the walkway, illumination plays a significant role in preventing trips and falls during trick-or-treating. Walkways should be properly illuminated to ensure visibility and safety, particularly in areas with changes in elevation or potential hazards. ASTM F1637-21 states that minimum walkway illumination must comply with local codes and ordinances. If local codes and ordinances do not address walkway illumination, then the recommendations set forth by the Illuminating Engineering Society of North America (IES) shall be used. 

Tripping can be a common hazard while trick-or-treating. Ensuring that elevation changes and illumination comply with safety standards such as the ASTM F1637-21 can help prevent children and adults from suffering a trip and fall while trick-or-treating and contributing to a safer environment for all pedestrians.

Ellen Szubski, Ph.D., CXLT, CPSI, AHFP, is a human factors consultant at The Warren Group. She earned a Doctorate of Philosophy in Human Factors Psychology and a Master of Science in Applied Psychology from Clemson University.  She did her dissertation on “The Influence of Pedestrian Biological Motion on Time-To-Collision Estimates at Night”.  She is also a Certified XL Tribometrist, Certified Playground Safety Inspector and a Certified Associate Human Factors Professional (AHFP). Prior to entering the forensic field, Ellen planned and conducted experiments for a major bicycle manufacturer. She also conducted laser strike perception studies for the Department of Defense.  Ellen applies her experience in Human Factors to the analysis of crash investigations and other personal injury matters. These matters often include collisions involving vulnerable road users and drivers, driver distraction, and slips, trips, and falls. She utilizes her knowledge of OSHA regulations, codes, and standards in her analysis of premises liability incidents and safety consulting.  Ellen is a current member of the Human Factors and Ergonomics Society (HFES) and it’s Forensic Professional Technical Group.

Human Factors and Halloween Hazards: Vehicle/Pedestrian Collisions

Author

Trick-or-treating is a fun and festive activity, but it comes with certain hazards that can pose risks to children and even adults. In addition to trip and fall hazards while trick-or-treating, there is also an increased risk of vehicle/pedestrian collisions due to the increased pedestrian activity in the roadway at night.

Child trick or treating during Halloween in the roadway.

At night, there are two significant problems facing drivers that contribute to pedestrian/vehicle collisions: the degraded visual abilities of drivers and the low contrast of pedestrians. The human visual system is severely limited at night. Both the visual ability to recognize objects and see fine detail, and the ability to recognize low contrast objects like pedestrians are diminished at night. In night, humans experience a loss of color perception and hue as well. Drivers are typically unaware of the extent to which their visual abilities are reduced at night, as suggested by the selective degradation theory which states that a driver’s ability to detect and recognize roadway hazards degrades with lower illumination, while their ability to steer the vehicle remains unchanged. The unchanged ability of a driver to maneuver a vehicle allows the driver to remain confident in their nighttime driving skills, despite their severely degraded visual capabilities in detecting and recognizing roadway hazards like pedestrian trick-or-treaters during Halloween.

Drivers face two significant problems while driving at night: the degraded visual abilities of drivers and the low contrast of pedestrians.

In addition to the degraded visual abilities of drivers, the low contrast of pedestrians within a roadway environment is also a significant problem that contributes to pedestrian/vehicle collisions at night. At night, a driver has decreased sensitivity to fine details, color, and contrast, therefore they are less likely to detect and recognize pedestrians. Pedestrians can enhance their visibility to drivers by increasing their contrast through visibility aids such as retroreflective material. Pedestrians can be made more conspicuous to drivers through the proper placement of appropriate visibility aids. Conspicuity differs from visibility such that a conspicuous object is defined as one that ‘grabs’ the observer’s attention with minimal visual search and is easily recognizable. A visible object is defined as an object that simply contrasts with the background. The more conspicuous the pedestrian, the less likely a collision between the pedestrian and driver. (Please see my previous article titled “The Big Difference Between Conspicuity and Visibility” for more information on the distinction between visibility and conspicuity.). Trick or treater pedestrians should aim to increase their conspicuity with active lighting or retroreflective materials while in the roadway during Halloween in order to enhance their safety.

In conclusion, the degraded visual abilities of drivers and the low conspicuity of pedestrians on the road contribute to pedestrian vehicle collisions at night. During trick-or-treating for Halloween, there is increased pedestrian activity in the roadway at night, increasing the risk of vehicle/pedestrian collisions. Drivers are largely unaware of their diminished visual abilities at night and may overdrive their headlights. Pedestrians typically lack sufficient contrast within their environment to be visible and conspicuous to drivers. An awareness of a driver’s degraded visual abilities at night in addition to decreasing vehicle speeds and increasing the conspicuity of pedestrians may help decrease pedestrian/vehicle collisions at night during Halloween.

Ellen Szubski, Ph.D., CXLT, CPSI, AHFP, is a human factors consultant at The Warren Group. She earned a Doctorate of Philosophy in Human Factors Psychology and a Master of Science in Applied Psychology from Clemson University.  She did her dissertation on “The Influence of Pedestrian Biological Motion on Time-To-Collision Estimates at Night”.  She is also a Certified XL Tribometrist, Certified Playground Safety Inspector and a Certified Associate Human Factors Professional (AHFP). Prior to entering the forensic field, Ellen planned and conducted experiments for a major bicycle manufacturer. She also conducted laser strike perception studies for the Department of Defense.  Ellen applies her experience in Human Factors to the analysis of crash investigations and other personal injury matters. These matters often include collisions involving vulnerable road users and drivers, driver distraction, and slips, trips, and falls. She utilizes her knowledge of OSHA regulations, codes, and standards in her analysis of premises liability incidents and safety consulting.  Ellen is a current member of the Human Factors and Ergonomics Society (HFES) and it’s Forensic Professional Technical Group.

What’s Up Doc? Collision Scene Documentation & Techniques

Author

A proper collision scene documentation, lovingly referred to as a scene doc, will make or break the investigation… guaranteed! While not necessarily all inclusive, here are a few evidence collection / documentation techniques that have served me well over the years.

Some, if not most, collision scene evidence is short lived, and tire marks Read More

Civil Twilight Pedestrian Collision: A Case Study

Author

Susan, a 45-year-old runner, was jogging in the early morning approximately an hour before sunrise, also known as “civil twilight.” Civil twilight occurs both before sunrise and after sunset when the sun is below the horizon and the sky is partially illuminated. Susan was wearing dark athletic clothing and grey tennis shoes for her morning run. She was running on the sidewalk in a suburban area and began to cross the four-lane road at an unmarked crosswalk. Read More

The 9-Cell Collision Matrix – The Environment

Author

“Was a dark stormy night as the train rattled on…” Anybody? 1985? Scarecrow?  Come on… this was when Cougar was still a Mellencamp! Ok… it was called Grandma’s Theme… you’ll have to look that one up… but as I sat down to write this blog on the environment, that song kept running though my head. If you look it up, it will have a similar effect… just a little warning.

In our last installment of the 9-Cell Collision Matrix let’s travel down the wet, slippery slope of environmental factors that can contribute to car crashes, and maybe take a closer look at the things around us, at or near our crash scene that may reveal some important clues. Read More

What You Don’t See Can Hurt You-Undercarriage Crashes

Author

A 43-year-old man driving his small vehicle northbound in the right lane of a rural two-lane paved road, was on his way to his favorite hunting spot in the early morning. He had two passengers with him—one in his front passenger seat and one in his back left seat. It was dark outside, and the weather was clear and dry. Along the rural two-lane road were large wooded private properties with no ambient lighting illuminating the roadway. Further up the road, a log truck began to turn left onto the road. Unable to entirely turn left in one fluid movement, the log truck Read More

The Difficult Task of Avoiding Pedestrians While Driving at Night

Author

An alarming 6,516 pedestrians were killed, and 54,769 pedestrians were injured as a result of traffic crashes in 2020 (NHTSA, 2022). A large majority (77%) of these pedestrian fatalities occurred in low luminance conditions such as nighttime while only 20% occurred in daylight (NHTSA, 2022). This dramatic difference between pedestrian fatalities during the night and day is seen even when controlling for driver fatigue and alcohol consumption (Owens & Sivak, 1996). This phenomenon prompts the question as what is so dangerous about being a pedestrian at night? Read More

The Collision Reconstruction Matrix – The Human

Author

Murder, suicide, deceit, and intrigue… car crashes? You bet! In our next installment of the 9-Cell Collision Matrix let us dive a little deeper into the glue that binds all this together, the human element.

Photo by Mark Turner

Let’s begin with the most basic human element at the root cause of car wrecks, our old friend inattention. Inattention… a vast word that encompasses many lackadaisical conditions. The daydreaming 16-year-old in math class, the radio knob turner, the back seat talker, the quarter pounder with cheese eater, and perhaps the most offensive, the cell phone user. All very dangerous behind the wheel, and one very dangerous to your future… as it turns out, you will always need good math skills… ask me how I know? Driving is of course a divided attention endeavor, Read More

The Best Use of Visibility Aids – Contrast

Author

There are various visibility aids marketed for vulnerable road users (VRUs). Here, the term VRU is used to describe unprotected road users such as pedestrians and bicyclists. Visibility aids are designed to increase a VRU’s contrast within their environment, making them more distinguishable from the background to a driver. These visibility aids can include both active and passive ways to increase the VRU’s contrast, therefore their visibility. As the name implies, active visibility aids actively transmit light and are powered by a source (i.e., battery powered bicycle headlights and taillights) while passive visibility aids passively reflect light coming from outside sources (i.e., fluorescent, and retroreflective clothing).

There are a wide variety of active visibility aids to choose from on the market. For example, Read More

Type ofLoss

Not sure what you're looking for?
Browse All

Select Loss Category
Select Sub-Category (choose category first)
View Now