The Silver Bridge Collapse: Don’t Blame the Mothman!

 

By Don Karol

Rumor has it that, just before the December 15, 1967, collapse of the US Highway 35 Bridge in Point Pleasant, West Virginia, a 7-foot-tall monster with large, piercing red eyes and huge, mothlike wings was seen lurking nearby, warning of the impending catastrophe. This “Mothman” was soon blamed for the tragedy in which 46 people died and 9 were injured. Of the 37 vehicles on the bridge at the time of the collapse, 31 fell with it, many plunging into the Ohio River. Fifty years after the collapse of what was then known as the Silver Bridge, paranormal speculation still swirls around the event, perpetuated by movies (like the Mothman Prophecies), legends, and myths. As a civil engineer, though, I put my trust in the laws of physics, materials science, and the findings of the NTSB investigation completed five decades ago, which proved without a doubt that the Mothman wasn’t to blame.

Silver Bridge, Point Pleasant, West Virginia
Section of Silver Bridge, Point Pleasant, West Virginia, that collapsed on December 15, 1967 (source: Herald-Dispatch)

The Silver Bridge collapse was the first significant highway accident investigation in NTSB history. Working with experts from the Federal Highway Administration, the states of West Virginia and Ohio, and leading engineering consulting firms, we determined conclusively that the cause of the collapse was an eyebar fracture in one of the bridge’s suspension chains. The fracture resulted from stress corrosion and corrosion fatigue that had developed over the bridge’s 40-year lifespan. Not surprisingly, no evidence was ever found connecting the Mothman to the failure.

This catastrophic event prompted national concern about the safety of bridges across the United States. President Lyndon B. Johnson ordered all US bridges to undergo safety inspections. Congressional hearings resulted in mandates requiring the US Department of Transportation to develop and implement National Bridge Inspection Standards. In December 1970, landmark legislation was enacted that established national requirements for bridge inspection and evaluation. One would think that these rigorous new inspection standards would take care of bridge failures forever. Unfortunately, during the past half century, that’s not been the case.

1983 bridge collapse in Greenwich CT
A 100-foot-long section of the Interstate 95 bridge over the Mianus River in Greenwich, Connecticut, collapsed June 29, 1983 (source: Bob Child, Associated Press)

On June 28, 1983, a 100-foot-long section of Interstate 95 (Mianus River Bridge) collapsed near Greenwich, Connecticut. Two tractor-semitrailers and two passenger vehicles went down with it, resulting in three fatalities and three serious injuries. We determined that corrosion-induced forces led to lateral displacement of the suspension assembly, which went undetected by the state’s bridge inspection and maintenance programs and ultimately led to the collapse.

On April 5, 1987, tragedy struck again when two spans of the New York State Thruway (Interstate 90) fell about 80 feet into the rain-swollen Schoharie Creek. Four passenger cars and one tractor-semitrailer plunged into the creek, and 10 people were killed. We determined that the New York State Thruway Authority failed to maintain adequate support around the bridge piers, leading to severe erosion in the soil beneath the bridge footings. We also determined that the state’s bridge inspection program was inadequate. Not surprisingly, neither the Mothman nor the Loch Ness Monster was seen in advance of this collapse to forewarn of the impending catastrophe.

1987 bridge collapse near Amsterdam, New York
Divers search for victims in the Schoharie Creek after the New York State Thruway bridge collapsed near Amsterdam, New York, on April 5, 1987 (source: Fred McKinney, Times Union)

Other notable bridge failures we investigated in the late 1980s involved localized flooding and water scouring. One collapse occurred on April 1, 1989, near Covington, Tennessee, when two columns supporting three bridge spans collapsed, sending an 85‑foot section of the US Route 51 bridge 20 feet into the Hatchie River. Five vehicles fell with it, killing eight occupants. Again, our investigation identified deficiencies in the state authority’s bridge oversight. In response to our investigations of these events, additional requirements were developed for periodic underwater inspection of bridges.

Probably the most memorable bridge collapse we investigated occurred 10 years ago in Minneapolis, Minnesota, when a catastrophic failure occurred in the main span of the deck truss in the Interstate 35W highway bridge. As a result, 1,000 feet of the deck truss collapsed during rush hour, with about 456 feet of the main span falling into the river. A total of 111 vehicles were on the portion of the bridge that collapsed; 13 people died and 145 were injured. We determined that a design error in the gusset plates compromised the bridge’s load capacity, causing it to fail under substantial weight increases. Our investigation prompted the development of additional bridge quality assurance and improved bridge inspection requirements.

2007 bridge collapse in Minneapolis, Minnesota
Interstate 35W bridge over the Mississippi River collapsed in Minneapolis, Minnesota, on August 1, 2007 (source: Peter Matthews, Polaris)

On December 15, as we mark the 50th anniversary of the Silver Bridge collapse, let’s focus on the infrastructure improvements we need still need to make five decades later rather than try to place the blame on mythical creatures like the Mothman. Throughout the NTSB’s history, we have investigated catastrophic bridge collapses with one goal in mind: preventing future tragedies. Despite efforts to continually enhance the quality of bridge inspections, unforeseen disasters continue to occur, highlighting the need to thoroughly inspect and replace bridges before they collapse. Supernatural forces do not bring down bridges; neglect does.

 

Don Karol is a Senior Highway Accident Investigator and National Resource Specialist in the NTSB Office of Highway Safety.

Episode 6- Stephanie Matonek

In this episode of Behind-the-Scene @ NTSB, we chat with Transportation Disaster Assistance Specialist, Stephanie Matonek. She discusses how she found her passion for the work that she does as part of the TDA team and path she took to get to where she is now. She also has a piece of interesting NTSB history that she shares with us.

Erik and Stephanie
Erik Strickland (l) interviews Stephanie Matonek (r) for Behind-the-Scene @NTSB

Get the latest episode on Apple Podcasts or on Google Play.

And find more ways to listen here: https://www.blubrry.com/behind_the_scene_ntsb/

How Employers Can Make Our Roads Safer

By Member T. Bella Dinh-Zarr, PhD, MPH 

“Safety should not be a competitive advantage.”

That’s the message I keep in mind every time I visit groups that represent employers, like the Network of Employers for Transportation Safety (NETS) which focuses on highway safety, or when I meet with the executives at individual companies, who may use many different modes of transportation for their businesses.

The NTSB is a unique federal agency because we are completely independent. Our agency has one simple but noble purpose: to prevent transportation-related deaths and injuries. We are on call 24 hours a day, 365 days a year, to investigate accidents, assist victims’ families, develop factual records, and recommend changes to make transportation safer. Unlike many government agencies, the NTSB has no regulatory authority, and we have no financial incentives to promote our safety recommendations. Our daily decision-making is guided by our values of integrity, transparency, independence, and excellence. We undertake investigations and make recommendations for the sole purpose of preventing future transportation disasters.

CMVSInfographicEmployers are uniquely positioned to meaningfully advance the recommendations that we make at the NTSB.  Over the years, we’ve issued over 14,000 safety recommendations to over 2,300 recipients, many of which are employers or groups that represent them. We know that if employers voluntarily implement our recommendations, our transportation system will be much safer. We’ve issued business-relevant recommendations related to installing recorder technology, developing fatigue management plans, requiring medical fitness, and many more—most of which are on our Most Wanted List (MWL).

Employers have a responsibility to address transportation safety. Nowhere is this more evident than for employers with vehicle fleets.  Many employers develop policies and procedures to keep their staff safe on the roads because they know that motor vehicle crashes are the leading cause of death among workers in the United States. According to the Bureau of Labor Statistics, from 2003–2015, there were more than 23,000 work-related motor vehicle deaths in the United States. The issues on our MWL, if addressed by employers, can help reduce this unfortunate statistic.

One way employers have helped advance safety—and can continue to do so—is by promoting evidence-based interventions like lowering the illegal BAC (blood alcohol concentration) to .05 (g/dL) or lower and implementing primary seat belt laws in the communities they serve. More than 10,000 people die in alcohol-related crashes every year. We’ve recently received attention because of our efforts to end impaired driving and our recommendation to change BAC laws from .08 to .05 BAC or lower. Many peer-reviewed studies have shown that such a law would prevent impaired‑driving crashes. While commercial drivers already are required to comply with a .04 BAC limit, employers can be an important influence in the lives of their employees, as well as in the communities in which they operate, by educating their employees and spreading the word about the effectiveness of a .05 BAC law.

Safety-conscious employers were some of the first and most vocal supporters of preventing distracted driving, long before distraction was a popular topic. Good companies didn’t just talk about distracted driving, they took action—as I’ve seen firsthand—to educate their employees and to change polices to prevent distracted driving.

American companies with large fleets also have been some of the most vocal supporters of the UN Decade of Action for Road Safety. They have worked hard to support international road safety, and have contributed to nontraditional traffic safety efforts, like helmet campaigns and infrastructure programs that improve the road environment, especially around schools.

Employers should also consider bringing vehicles with collision avoidance technology into their company fleets. Systems such as collision warning and automatic emergency braking help keep drivers safe by mitigating or even preventing crashes. Employers could install onboard vehicle monitoring systems and recording devices, such as cameras, to help monitor driving activity and unsafe practices. These technologies require an investment, but that investment will go a long way toward reducing insurance and workers’ compensation costs—and ultimately toward preventing injuries and saving lives.

There are many employers already considering and incorporating these technologies to improve safety; however, the more who join these industry leaders, the more lives will be saved. We can’t overstate the influence employers have, not just on their employees, but on their employees’ families and on their entire communities. Employer support of safety initiatives can be far-reaching. Companies that make safety a priority tend to have employees who make safety a priority. What employees learn about safety—whether related to distracted, impaired, or fatigued driving, or the value of collision avoidance technologies in vehicles—goes home to their families and spreads beyond to the entire community. Employers already have made a positive difference in many areas of traffic safety and employers will be vital to the effort to achieve zero deaths on our roads.

 

For more information on motor vehicle safety at work, visit the National Institute for Occupational Safety and Health website: https://www.cdc.gov/niosh/motorvehicle/resources/crashdata/facts.html

 

 

 

Inspiring Youth Safety Leaders

By Nicholas Worrell, Chief, NTSB Safety Advocacy Division

As an NTSB safety advocate, I serve the American people by promoting safety improvements that will save lives, prevent injuries, and preserve property on the nation’s roadways. I work to end distracted and impaired driving, and I encourage greater use of seat belts and child restraint systems.

One way I get my advocacy message across is by speaking on safety issues. I recently attended the National Black Caucus of State Legislators (NBCSL) Annual Conference in Indianapolis, Indiana. The theme this year was “Racing Towards the Future: Leading in a Time of Change,” though, from a transportation safety perspective, it seems like the future is racing toward us. We are living in an age when everyone, everywhere is connected by technology. In the span of a decade, smartphones have gone from the hot new item to a staple of modern life. But to avoid tragedies, all of us must keep our hands, eyes, and minds on the road—especially our youth, who lack driving experience.

At the conference, I sat on a panel with NBCSL corporate roundtable (CRT) members to address students from Warren Central High School in Indianapolis. Our goal was to educate, empower, and engage the youth on a variety of topics. From my perspective, their race toward the future, and the future’s race toward them, are both givens; the challenge will be for them to lead during changing times. I spoke to them about the significance of making good decisions that would have a positive impact on their lives in years to come. I stressed to them that motor vehicle crashes are the leading cause of death for teenagers, killing more young people every year than suicide, drugs, violence, and alcohol abuse combined. In the last decade, more than 51,000 people between the ages of 15 and 20 died in traffic crashes. That’s nearly 100 people each week! My message, then, was for these youth to act intentionally; to think about consequences up front. Not only are those good leadership habits, but they’re also excellent safe driving strategies.

NBCSL
Nicholas Worrell with Warren Central High School Principal Rich Shepler and students

I encouraged the audience members to become leaders among their peers. Fatigue, impaired driving, and distracted driving are all factors that can endanger young drivers’ lives. A big part of racing towards the future is bringing about widespread change at a pace that matches other changes coming about—like curbing distracted driving at a clip that keeps up with the developing technology. Keeping up with these changes will take time and commitment, and will require three things: good education and outreach, good laws, and good enforcement.

NBCSL 2
Nicholas Worrell joins National Black Caucus of State Legislators corporate roundtable members with Warren Central High School students

The race toward the future must be a race on the Road to Zero Fatalities; however, racing toward the future is more than giving teens a driver’s license or a car. As the CRT members discussed at the conference, today’s teens must meet tomorrow’s challenges with values like responsibility, commitment, passion, initiative, focus, action, persistence, growth, character, goals, gratitude, servitude, and courage, among other things. Racing toward the future will require a great deal of toil, and our youth will benefit from applying the lessons learned before them. Along with my colleagues on the panel, I offered my best advice and my own story to help guide them.

In 2016, we lost more than 37,000 lives on our nation’s roads. As we race toward 2018, what changes will we make to help prevent accidents, injuries, and fatalities? What steps can each of us take to prepare our youth for a brighter future? What stepping stones can we lay for students like those at Warren Central High?

Whether you teach students, mentor younger colleagues, or serve as an example to children, younger family members, or your peers, you, too, can lead during a time of change. The future is racing toward us; the time to prepare the next generation is now.

Williston and Beyond

By Member Christopher A. Hart

A car that is fully controlled by a computer doesn’t get drowsy or distracted. It doesn’t get drunk or impaired by other drugs. If it’s instructed not to go above the speed limit, it won’t. Human error, which is at least partly responsible for 94% of today’s highway crashes, can largely be eliminated if the human driver becomes just another passenger. And with the unacceptable carnage of more than 37,000 deaths in motor vehicle crashes in 2016 alone, we can use all the help we can get. There’s no question that the potential benefits of autonomous vehicles are nothing short of phenomenal.

Getting there, however, will not be as easy as many people think. We recently held a Board meeting to consider the crash in 2016 of a partially automated Tesla into a tractor‑trailer near Williston, Florida. The driver wasn’t paying attention to the road as he should’ve been, and the system allowed the driver to use its “Autopilot” feature in places where it wasn’t designed to operate. The automation system used torque on the steering wheel as a proxy for driver engagement and alerted the driver if too much time passed without detectable movement on the wheel, but the driver treated the alerts as nuisances, dutifully applying torque each time the alert sounded before taking his hands off the wheel again. Although the driver was ultimately responsible for the resulting crash in which he tragically lost his life, the automation allowed him to make unsafe choices.

2015 Tesla Model S 70D car involved in the May 7, 2016, Williston, Florida crash
2015 Tesla Model S 70D car involved in the May 7, 2016, Williston, Florida crash

Flash back to 1914. An airplane flies past reviewing stands full of spectators. The pilot holds his hands high in the air to demonstrate that the airplane is flying itself. The plane makes another pass, then another. According to aviation lore, by the third pass, the pilot, Lawrence Sperry, is walking on the wings. Sperry was showing off his entry in an international aviation safety exhibition: the world’s first primitive autopilot, the gyroscopic stabilizer. It allowed a plane to fly straight and level without pilot input for short periods at a time.

In the years since, aircraft automation has become much more sophisticated. In addition, planes now have systems that sense terrain, they use GPS to know where they are, and they employ a vehicle-to-vehicle technology called a traffic collision avoidance system to help them avoid other planes. Thanks, in large measure to these technologies, aviation has become much safer. Yet, in 2013, nearly 100 years after Sperry’s demonstration, Asiana Flight 214, with more than 300 people on board, approached San Francisco International Airport too low and too slow and crashed into a seawall, killing three passengers.

Fire damage to the fuselage of Asiana flight 214
Fire damage to the fuselage of Asiana Flight 214

The Asiana crash demonstrated automation confusion: the pilot thought that the auto‑throttle was maintaining the speed he selected, but he had inadvertently and unknowingly caused the auto‑throttle to become inactive. It also demonstrated that, due to longstanding overreliance on the automation, the pilot’s manual flying skills had degraded so much that he was uneasy about landing the plane manually on a 2‑mile‑long runway (that’s a long runway!) on a beautiful, clear day.

We’ve investigated automation-related accidents in all modes of transportation. In fact, our investigators see accident after accident involving problems with the interface between the automation and the human operator; we also see far too often that humans are not reliable about passively monitoring automation. And in cases like the Asiana crash, we see that humans get rusty when they don’t use their skills.

The Williston crash showed error types that are not surprising with what’s called level 2 automation. The human driver was responsible for monitoring the environment, but the automation allowed him to shirk this responsibility. This result was foreseeable, given the unfortunate use of the moniker “Autopilot,” which may suggest to the ordinary driver that the car can fully control itself (as compared with pilots, who know that they must still be engaged even when their airplane is operating on autopilot). Thus, one lesson learned is that if the automation should only be usable in certain circumstances, it should be “geo-fenced” so that it will work only in those circumstances instead of depending on the driver to decide appropriately.

What can we expect as our cars move beyond level 2? The aviation experience has demonstrated that as automation increases, so do the challenges. As automation becomes more complicated, drivers are less likely to understand it, and as automation becomes more reliable, drivers will become more complacent, less skillful, and less vigilant to potential failures. As a result, if a failure occurs in a more complicated and reliable system, the likelihood increases that most drivers will not be able to recover successfully from the failure.

In the Asiana investigation, we found that the airline used the available automation as fully and as often as possible. After the crash, we recommended that the airline require more manual flying, both in training and in line operations—not because we’re against technology, but because we see what can happen when pilots lose their skills because they’re not using them.

Then there’s the question of removing the driver altogether. Airliners will have pilots for the foreseeable future because aviation experts have not yet developed a “graceful exit” regarding failure of the automation or what to do if it encounters unanticipated circumstances. Similarly, drivers will be in the picture until the industry develops a graceful exit for their automation failing or encountering unanticipated circumstances . . . and unanticipated circumstances are certainly abundant on our streets and highways.

In every one of our investigations, we study the human, the machine, and the environment. Even across modes, humans and their interactions with automation are a common denominator in an accident’s probable cause. For 50 years, we’ve been finding answers to help the transportation industry save lives, and when our recommendations are put into practice, the industry and the public generally realize safety benefits. We are excited about the opportunities to use the lessons we’ve learned over these many years to help the transportation industry move toward safer vehicles, regardless of who (or what) is operating them.

We’ve come a long way since Lawrence Sperry’s gyroscopic stabilizer, but as accidents like Asiana and Williston show, we’ve still got a way to go before automation can significantly reduce fatalities on our streets and highways. We look forward to continuing to work with vehicle manufacturers to help them develop safer and more reliable automated transportation.

Episode 5- Nathan Doble and Ivan Cheung

In this episode of Behind-the-Scene @ NTSB, we chat with Transportation Research Analysts, Nathan Doble and Ivan Cheung. They share the professional journeys they took to get to the NTSB and discuss their latest report, Reducing Speeding-Related Crashes Involving Passenger Vehicles

IMG_6586
Nathan Doble (left), Ivan Cheung (center), and host Erik Strickland (right) discussing the Speed Report. 

Get the latest episode on Apple Podcasts or on Google Play.

And find more ways to listen here: https://www.blubrry.com/behind_the_scene_ntsb/

Disconnect this Thanksgiving

By Chairman Robert L. Sumwalt

Before the roads become packed with young adults returning from college, out-of-town visitors arriving, and last-minute trips to the store for that missing item in Aunt Ida’s stuffing, I wanted to get in a few words about focusing on the drive this Thanksgiving.

If you’re driving, put down the phone. Better yet, put it in the glove compartment, or, if you’re driving with others, hand the phone over to someone you trust.

There’s still time before you get on the road to make arrangements; you don’t have to try to settle things while you drive. If you’re driving home from college, make sure that your parents know to leave a message if they call because you’re not answering the phone while driving. And say your goodbyes to your peers at school and not while you drive. Let your friends know in advance that the driver is out of contact until the drive is over, end of story. No texts, no tweets, no e-mails, no calls.

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Chairman Sumwalt talks with survivor advocates at the Act to End Deadly Distractions roundtable 

For you parents: As a parent myself, I know how much we worry. But don’t call your children while they’re driving. Distracting them from the driving task can cause far more heartache than not knowing exactly where they are and how they’re getting along.

Back on the home front: If you need to call back to your house to see if you forgot to stock up on something for the guests, do it from the store parking lot. If you’re a guest on the way and you need to tell your hosts your progress, do it from a rest area.

Thanksgiving is a joyous American holiday, and it kicks off our festive holiday season. While we’re gathering with friends and family to give thanks for all we’ve got, let’s not open ourselves up to a terrible loss.

Mom, dad, kids, sis, boyfriend, girlfriend, fiancée, spouse, buddy… I won’t take your call and I won’t answer your text while I’m on the road. Our connection doesn’t depend on our tweets, text messages, photos, or phone conversations while driving; it’s in our hearts, not our heart emojis. It’s far better to lose the electronic representation of a loved one for a few minutes or hours than to lose a loved one—or cause somebody else to lose a loved one—forever.

Last April, StopDistractions.org, Drive Smart VA, and the National Safety Council worked with the NTSB to present a roundtable, “Act to End Deadly Distractions.” The roundtable brought together survivor advocates with other experts to tell their stories and share tools they’re using in their fight against distracted driving. Some of the survivor advocates at this roundtable will see empty seats this year at the Thanksgiving table. As one of the participants put it, “this isn’t a club any of us wanted to be in. We don’t want to be here; we want to be home with our loved ones . . . that was taken from us.”

Thousands of people “join the club” of distracted driving survivors or victims every year. But this Thanksgiving, we can all act to lower this number and get home safely to our loved ones by disconnecting while we’re driving.

Click on the link to see a few moments from the “Act to End Deadly Distractions” roundtable (just not while you’re driving).

 

The Official Blog of the NTSB Chairman

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