Why Are Speeding, Distraction and Fatigue the Biggest Risks for Drivers?

Originally published in Fleet Management Weekly 08/18/2021

By Paul Atchley, PhD, eDriving’s Brain Science Advisor

In a recent article, we examined what it takes to be a safe driver. In that post we explored the skill of driving as described in the SPIDER model (Visual Scanning, Hazard Prediction, Identification, Decision Making and Execution of a Response ) by Donald Fisher and David Strayer. In this article we will examine the other side of the safe driving equation; risk, and will explore why behaviors such as Speeding, Distraction and Fatigue pose such a threat (the “Triple Threat”).

In my work with safety professionals, I have occasionally heard variations on the following question: “Why should we ban phones when drivers engage in all sorts of risky behaviors while driving?” The answer requires that we understand the components of risky behavior and how they impact crash risk and severity. Overall risk equals the sum of the complexity of the non-driving task plus how engaging that task is, multiplied by the overall time the task takes. The severity of a crash depends upon the degree that the non-driving task reduces the opportunity to mitigate a crash, if one is imminent.

The complexity of a non-driving task is quantified by how much it interferes with the driving task. For example, eating interferes with the manual component of the driving task, but it has little impact on the visual or cognitive aspects of driving, so it is low in complexity. A hands-free cell phone conversation impacts the cognitive and visual aspects of the driving task (hands-free cell phone conversations reduce visual scanning of the roadway), but it has little impact on manual control. Texting impacts manual, visual and cognitive components of driving, so is highly complex.

Task engagement refers to the degree to which the non-driving task demands driver attention. For example, listening to a radio is a passive task. The human brain can filter out the radio program to focus on driving, so it contributes little to crash risk. On the other hand, a cell-phone conversation requires driver attention. It is incredibly difficult for drivers to ignore a cell-phone conversation and return focus to the roadway. In-car conversations are equally as engaging, but when a driver and passenger are talking, the conversation is modulated by a shared awareness of the driving demands.

The duration of the non-driving task compounds the level of risk. The longer the task, the greater the overall risk and chance of a crash. One reason that studies typically fail to find a difference in risk between hand-held and hands-free phone use is that the time it takes to dial is very short compared to the overall length of a conversation. Thus, most of the risk is due to the time spent with the brain on the conversation and not from dialing.

Finally, risk of a crash is impacted by whether or not the non-driving task interferes with the ability of a driver to avoid or mitigate a crash. One reason speeding is so risky is that it both reduces the time a driver has to make a decision and execute a response to avoid a crash. Also, if a crash occurs, it is with more force and thus more likely to be severe. Fatigue can similarly blunt responses or eliminate them entirely. Tasks that reduce visual scanning and the ability of the brain to process visual information (phone use in ANY manner) similarly reduce crash mitigation and increase crash severity.

So, in summary, the answer to why we target Speeding, Phone Distractions and Fatigue is that each of these threats contributes to greater overall risk of a severe crash compared to other risks drivers take.

About Paul Atchley

eDriving’s Brain Science Advisor, Paul Atchley, PhD, is the University of South Florida’s Senior Associate Vice President and Dean of Undergraduate Studies. As a Professor of Psychology, he specializes in research in cognitive factors, including the implications of multitasking on driving.

About eDriving

eDriving, a Solera company, revolutionized driver risk management with the introduction of the world’s first defensive driving CD-ROM in the 1990s. Today, eDriving helps organizations around the world to reduce incidents, collisions, injuries, license violations, carbon emissions, and total cost of fleet ownership through its patented digital driver risk management programs.

At its heart is the Mentor by eDrivingSM smartphone app that identifies risky driving behaviors for intervention and safe driving habits for recognition. In-app features include micro-training and coaching, gamification, collision reporting, vehicle inspections, and an individual FICO® Safe Driving Score validated to predict the likelihood of being involved in a collision. Through our five-stage, patented Crash-Free Culture® risk reduction methodology, eDriving helps organizations embrace safety and reduce risk for Sales, Service, Delivery and Warehouse drivers, all within a privacy-first, data-secure environment.

eDriving is the digital driver risk management partner of choice for many of the world’s largest organizations, supporting over 1.2 million drivers in 125 countries. Over the past 25 years, eDriving’s research-validated programs have been recognized with over 100 awards around the world.