The American Medical Association recognized obesity as an official disease in 2013. With nearly 36% percent of all Americans the age of 20 or older struggle with obesity, it is clear that this is a serious issue in our country, one that we must be willing to address and adjust to as the nation continues to make healthy lifestyles a priority.
Are Obese Individuals Less Safe in Their Vehicles?
According to a study published by researchers at the University of Michigan's Transportation Research Institute, obese passengers are far more likely to die in car accidents because safety belts are not designed to fit their frames properly. A follow up study completed in April 2012 by researchers at the University of Buffalo revealed that not only do safety belts not adequately protect obese drivers and passengers, these individuals are far less likely to even attempt to wear restraining belts, due to their ill fit and discomfort. This only increases the risk of their mortality in the event of an accident.
In the original study, researchers showed that obesity decreased the effectiveness of preventing injuries because the passenger's increased size changes the routing of the belt relative to the underlying skeletal structures. Increases in Body Mass Index (BMI) resulted in both significant forward shifting and lengthening of the lap belt. This creates excess slack in the restraint system, allowing for increased passenger movement in a crash.
In frontal crashes in particular, the increased seat belt slack is likely to contribute to increased passenger contact with the car's interior parts and, as a result, more severe injuries. In fact, a separate study published in the American Journal of Emergency Medicine found that a moderately obese driver faces a 21% increased risk of death in a car crash, while a morbidly obese individual is 56% more likely to die in a crash.
What Can Be Done About Lack of Seatbelt Safety?
While seatbelts may not be as effective for obese passengers as for those with a normal BMI, they won't help at all if the individual chooses not to wear a safety restraint. According to the results of the University of Buffalo study, obese drivers and passengers are 67% less likely to wear a seatbelt than their normal weight peers, likely because they have more difficulty buckling a standard sized safety belt. Not buckling up clearly puts obese drivers at even greater risk of death than a poorly fitted belt.
In reviewing evidence from all the relevant studies, it becomes clear that automakers need to do something to address the safety of the ever-heavier American population. Dr. Dietrich Jehle, Professor of Emergency Medicine at the University of Buffalo and co-author of the 2012 study says, "We need to do something (to address belt safety), since one-third of the U.S. population is overweight and one-third is considered obese. How can we make it more likely for people, including the overweight and obese, to wear seatbelts?"
Simple Solutions to Increase Safety for Obese Individuals in Cars
The following recommendations have been made for improved safety for obese individuals:
- Extend the range of adjustable seats
- Petition car manufacturers to also design and test interiors with obese crash test dummies
- Encourage obese drivers towards purchasing larger vehicles which are designed with more space between the seat and the steering column
- Improve understanding about seatbelt safety and the need for any type of restraint in a vehicle
Unless and until some seatbelt and test dummy design changes are implemented, obese passengers will continue to be at greater risk of sustaining serious injury in vehicle accidents.
The Crash Dummy Issue: What Does the Modern American Look Like?
One of the biggest issues is obtaining better data and testing in regards to obese passengers and drivers. While the general size and weight of the American public changed, crash test dummies remained relatively the same in recent years—they were not being adjusted for obese individuals according to the head of the biosciences group at the University of Michigan Transportation Research Institute. Without any HTSA-approved obese test dummies, little improvement can be made in this area of road safety.
"One-third of Americans are overweight. Another third are obese, so it becomes a fairly significant issue when it comes to vehicle safety and design," Jehle says.
In response to continual concerns, Humanetics Innovative Solutions, the U.S. manufacturers of crash test dummies, began to develop obese crash test dummies for the market in October of 2014. However, the NHTSA has yet to utilize this dummy in its program for safety testing.
While seatbelts are cited as the single most important thing that drivers and passengers can do to help lessen the risk of injuries or death in a crash, obese people are not getting the full protection due to incorrect sizing. Seatbelts are designed to work for the crash dummies they are tested on—which do not reflect the average size of Americans in today’s society.