ANN ARBOR, MI – Researchers try to put it delicately, but the U.S. population is aging rapidly and becoming so fat that new types of safety systems will have to be engineered specifically to protect them in crashes.
Myriad new technologies are being researched or already are available that safeguard drivers, passengers and pedestrians from a wide array of threats, but the growing demographic changes related to body weight and age add a new challenge to even the most commonplace safety devices.
Seatbelt and airbag designs are being developed that can adapt to the increased heft and different biomechanics of obese occupants as well as protect the more delicate internal organs and brittle bones of a skyrocketing number of drivers and passengers 70 years of age and older.
“The aging and fattening of the population will change the injury problem in crashes,” says University of Michigan researcher Jonathan Rupp at a U of M Transportation Research Institute conference here.
Right now, 27% of the U.S. population is considered obese, Rupp says, and the rate of obesity is increasing by 0.5% to 0.6% per year with no sign of letting up, according to the Centers for Disease Control and Prevention’ behavioral risk factor surveillance system.
And Rupp points out these estimates are based on self-reported information where people typically underestimate their weight and overestimate their height. Most independent estimates peg the nation’s obese population about 7% higher.
Obesity mainly affects injury risk in frontal crashes, Rupp says, because a heavier than normal occupant requires a bigger, stiffer airbag and wider, stronger seatbelt for proper restraint.
Obesity limits the effectiveness of conventional safety belts because they fit poorly and are unable to apply crash forces to the strong, bony parts of the anatomy, especially the pelvis.
This will lead to the introduction of more adaptive restraint technologies that can customize belt forces to each occupant and to devices such as inflatable seatbelts that can spread impact forces over a larger surface area, Rupp says.
Another major demographic trend, aging of the U.S. population, also is driving the movement to more adaptive restraint technologies.
“There is a subset of fatal frontal crashes that are not very severe, where the vehicle actually looks like it performed pretty well afterwards, but the person (who died) is very old, or very obese,” Adrian Lund, president of the Insurance Institute for Highway Safety, tells Ward’s.
“I think there is some evidence in the data,” Lund says.
According to the U.S. Census Bureau, the number of Americans 65 and over will rise from about 40 million today to about 87 million by 2050. And in the same time frame, those 80 years and older will outnumber all other age segments in 5-year increments, ranging from 5-9 years to 75-80 years.
Fatality rates per 100 miles (160 km) driven currently soar after age 70, especially in frontal crashes because the elderly are more frail and vulnerable to injury by high crash forces. That suggests significant safety changes will be required to keep fatality and injury rates in check as time goes on.
However, Lund points out data that show older drivers also are good at limiting their risk of becoming involved in crashes by becoming more cautious.
Nevertheless, Lund acknowledges that, “At some point you do become old and frail, and when that frailty occurs, it is hard to protect people.”
Kurt Fischer, a senior staff engineer at, a major safety-systems supplier, says current and future airbag systems can adapt the stiffness of an inflating bag to occupant size, position and weight, by using special tethers and vents.
Seatbelts also can be equipped with load-limiting devices that enable them to stretch and manage high crash energy for both large and small occupants without exerting too much force in specific areas, Fischer says.
An “active buckle lifter” concept is being touted byas well. It automatically extends the seatbelt buckle 3.5 ins. (90 mm) for two seconds after the driver or passenger sits, making it more convenient for a large or elderly person to buckle up.
Additionally, the buckle lifter reduces belt slack during dynamic driving conditions to keep the belt snug and occupant in position in case there is a crash.
NHTSA’s Lengthy Agenda
Worries over texting and other forms of distracted driving have dominated the automotive safety landscape for the past several years, and distracted driving remains a controversial.
But the recent UMTRI conference reveals independent researchers and the National Highway Traffic Safety Admin. have an ever-widening number of vehicle safety concerns.
In addition to obesity and age issues, they are looking at everything from developing in-vehicle blood alcohol detection systems to preventing computer hackers from attacking the electronic systems in cars and trucks.
Crash avoidance, automatic emergency braking, new types of crash tests and better ways of treating the injured after a crash all are on NHTSA’s lengthy agenda to make vehicles and roads ever safer.
And these targets are in addition to recent mandates that already are being set into motion regarding improved side-impact protection and ejection mitigation during vehicle rollovers.
Traffic deaths hit a record low 33,186 in 2009, but NHTSA is not celebrating. Instead, it is looking to ratchet up new rules because it anticipates fatality rates increasing economy improves and vehicle miles traveled, a key safety index, rise.
Even though enormous progress has been made, safety proponents say motor vehicle crashes remain the leading cause of death in the U.S. for ages 4 to 34. Crashes also are the fourth most common cause of non-fatal injuries treated in emergency rooms, and the annual economic cost of these injuries is estimated at $231 billion.
“The safety community has a lot of work to do,” says John Maddox, associate administrator-Office of Vehicle Safety Research at NHTSA.
“There are plenty of opportunities. The fortunate side of this problem is there are many ways to reduce the problem. We just have to figure out which ones are most effective and which ones we can afford to do,” adds IIHS’ Lund.
Four Key Areas of Research
NHTSA has divided its research initiatives into four areas: normal driving, crash imminent, crash event and post-crash, Maddox says.
Normal driving includes driver distraction, drowsy driver detection, blind-spot detection, and alcohol detection.
Vehicle electronics issues, including software strategies and validation requirements, electromagnetic compatibility and cyber security also are included in this category, as well as quiet-car detection for pedestrians.
Devices that can prevent alcohol-impaired drivers from operating their vehicles are of particular interest to the automotive safety community because crashes involving alcohol are responsible for more than 10,000 deaths every year, almost a third of all traffic fatalities.
IIHS estimates 90% of these fatalities could be eliminated by ignition interlocks that sense blood-alcohol levels above the legal limit.
Developing a non-invasive technology to measure driver-blood-alcohol levels is part of a 5-year, cooperative program between NHTSA and the auto industry, intended to support a non-regulatory, market-based approach to preventing drunk driving, Maddox says.
NHTSA sources say even though electronic flaws have been ruled out as a cause of sudden unintended acceleration in Toyotas, the agency still wants to regulate numerous aspects of vehicle electronics.
That’s because electronics are starting to control almost all areas of the vehicle, and they could be vulnerable to an increasing number of new threats, from on-board tampering to hacking and malicious external control.
NHTSA’s “crash imminent” category has the safety agency looking into forward-crash warning and automatic braking systems such as the Mercedes-Benz Distronic option, as well as Volvo systems that detect and brake for pedestrians, to see how these technologies can be migrated to more vehicles.
The agency is especially interested in these areas as they relate to heavy trucks, which are set to be regulated more in the future in the U.S. and Europe. Driver drowsiness and inexperience are blamed for a number of horrific, highly-publicized deadly crashes.
The European Commission already has mandated that by 2014, all heavy trucks and buses must be equipped with lane-departure warning and automatic emergency braking systems.
The crash-imminent segment also includes study of vehicle-to-vehicle and vehicle-to-infrastructure communications and lane-departure warning systems.
Advanced Airbags, Adaptive Restraints
In the “crash event” grouping, NHTSA is stressing advanced airbags, adaptive restraints, child side-impact regulations, oblique, offset frontal crash testing, rollover issues and elderly occupants – in addition to how this all affects the trend to smaller, more fuel-efficient cars and trucks.
For vehicle-pedestrian impacts, regulators are eying new hood and bumper designs that will lessen injuries.
On the heavy-truck side, the agency is looking at preventing so-called “underride” issues, where cars can dive under trailers in collisions.
Oblique-angle testing, where two vehicles are crashed head-on at a 15-degree angle, is becoming a hot-button issue with safety advocates because these types of crashes are producing a high number of fatalities at relatively low speeds even when seatbelts and airbags do their jobs.
That’s due in part to the impact angle, which is so slight, the vehicle body structure cannot properly manage the crash energy.
Advanced automatic-crash notification is the final major category of NHTSA’s investigation.
In the event of a crash, the agency would like to see key information about the severity of the collision such as whether occupants were belted during the impact transmitted from the vehicle to appropriate medical response teams.
Such information, using algorithms created by a CDC expert panel, could predict the probability of severe injury and speed response time. It also could help first responders determine when an emergency medical evacuation helicopter is required, or when an ambulance might not even be necessary.
In addition to these efforts, NHTSA is looking into the safety of EVs and EV charging, and smarter crash dummies.
Better Drivers Through Technology
But safety researchers agree that higher seatbelt use rates (now about 85% in the U.S.) and more responsible, attentive driving could have a far greater impact on vehicle safety than all the new technologies.
In other words, what is needed most is not smarter crash dummies, but smarter drivers.
But if drivers cannot be made smarter and more skillful with education and training, then technology may be able to compensate to a degree.
“The biggest bang for the buck, in the near-term, is probably crash avoidance,” says IIHS’ Lund.
“We’ve always known that the best crash is the one you can prevent, but we’ve never been too good at that. The idea of getting drivers to be better drivers has been very difficult. But now we’ve got all this new electronic technology that can help us protect ourselves.”
“With forward-collision warning, the car will let you know if you are not paying attention. And if you get too close to a car in front, the car will warn you and maybe even apply the brakes,” Lund says.
“All this electronic technology is the most tantalizing area. It’s the first time we have some real promise that maybe we can reduce driver error in crashes.”
Now all that’s needed is technology that automatically steers Americans into the gym and away from fatty foods.