Category Archives: Truck Safety

Understanding Underride VIII: Making the Case for Comprehensive Underride Protection Legislation

The basic problem of truck underride is the fact that there is a geometric mismatch between the large trucks and the smaller passenger vehicles. Crush zones are structural areas in a vehicle that are designed to absorb energy upon impact in a predictable way. However, upon collision of a passenger vehicle with a truck, there is no opportunity for engagement of the passenger vehicle crush/crumple zone with a solid portion of the truck.

The result? The crashworthiness of the passenger vehicle is not initiated. The car is allowed to go under the truck and the first point of impact is in the Passenger Occupant Space. The passengers are left vulnerable to horrific injuries and violent deaths.

In fact, although underride deaths are vastly underreported and undercounted, FARS data from the NHTSA show that hundreds of people die every year from truck underride passenger compartment intrusion (PCI). NHTSA reported 4,006 underride deaths from 1994 to 2014.

The rear underride guards, which are installed on semi-trailers, are supposed to prevent underride. But the IIHS, in 2011 and 2013, conducted crash testing which proved that the guards of eight major trailer manufacturers, though designed the meet the 1998 federal standard, too often fail. Subsequently, improved rear underride guards and side guards have been crash tested by the IIHS; crash dummies emerge with survivable results.

The majority of the large trucks on the road either have weak, ineffective rear underride guards – even though they meet the current federal standard – or none at all (as in the case of exempt single-unit trucks) or improperly maintained rear guards (initially known as ICC bumpers, later as Mansfield bars, or sometimes as Rear Impact Guards or RIGs). In addition, there is currently no federal requirement for commercial motor vehicles to have side guards – despite the fact that there is normally 4 feet between the bottom of the trailer and the road. And, although Europe has standards for Front Underrun Protection, the U.S. does not.

There were 340,000 large trucks manufactured in 2015. The majority of those have weak rear guards and no side guards. Volvo Trucks produces tractors with front underride protection in Europe but not on their North American trucks. There are nearly 2 million semi trucks in operation in the U.S. and around 5.6 million semi trailers. These drive around every day on our roads putting travelers at risk of Death by Underride.

The truck industry has known about the problem of underride for over a century. In fact, a patent was filed for a side guard in 1913. In response to the rear underride death of actress Jayne Mansfield in 1967, we saw some improvement in rear underride protection with a 1998 standard – although you will notice that that took 31 years to achieve and it still falls short of what is technologically possible some 50 years after her death.

The government is also well aware of the side underride problem. On March 19, 1969, the FHWA indicated in the Federal Register, in an analysis on rear underride rulemaking, that they intended to extend underride protection to the sides of large trucks after further studies. However, DOT has not done so and the industry – despite some voluntary improvement in response to appeals from victim families armed with information on the IIHS crash testing – has not shown an ability or willingness to solve this problem on their own.

As David Ward recently said, at the Road to Zero Coalition October 2017 quarterly meeting, there will always be a strong need for regulation and/or fiscal incentives to break market failure. Only then will we see 100% adoption of comprehensive underride protection. In fact, trailer manufacturers have said that a mandate would lift the burden from them; they would no longer have to persuade their customers to buy safer trailers.

The underride problem has been documented in numerous studies. The IIHS petitioned NHTSA in 2011 and the NTSB made recommendations in April 2014 that NHTSA initiate underride rulemaking to address safety vulnerabilities. The Volpe National Transportation Systems Center has recognized the problem and has worked with numerous Vision Zero Cities to install side guards on city trucks in order to protect Vulnerable Road Users.

A comprehensive underride protection rule, STOP Underrides!  because it will include single-unit trucks — will make it easier for cities throughout the U.S. to protect vulnerable road users. Every truck that drives on their streets will be equipped with comprehensive underride protection – a significant victory in the battle to create safer mobility for pedestrians, cyclists, and motorcyclists, as well as passenger vehicles.

With comprehensive underride protection installed on the entire large truck fleet, we should see a significant decrease in the 4,000 truck crash fatalities/year (4,713 in 2016), along with a major reduction in debilitating injuries. Truck crashes can be made more survivable.

Or do we want to continue to allow people to die?

Understanding Underride I to VIII: A Source of Helpful Information on Truck Underride

In order to gain a basic understanding of the deadly but preventable truck underride problem, a compilation of helpful resources is provided below.

A complete list of posts on Understanding Underride can be found here:

WUSA9 recently began an extensive investigation into truck underride. The segments which have already aired are listed here. They plan to shed light on the problem until it is adequately addressed in this country.  See all of the videos here: WUSA9 Underride Series Sheds Light on Deadly Truck Underride Tragedies & Solutions

The STOP Underrides! Act of 2017 has been drafted by Senator Kirsten Gillibrand. She is working with Congressman Steve Cohen, who will be drafting a House Companion Measure.  They are both seeking Republican co-leads for this long-overdue, life-saving legislation.

On October 12, 2017, staff from Congressional Offices gathered to hear presentations from five experts on the topic of truck underride to better understand the need for the STOP Underrides! bill. The presentations were followed by a question & answer period as legislative staff sought to understand the problem and solutions of deadly but preventable underride crashes.

The presentations can be found here: Underride Briefing on The Hill; Video Excerpts of Panel Discussion on October 12

Another series of posts on underride is titled Underride 101:

Truck Underride 101: Discussion Topics

I. When Will We Tackle Truck Underride?

Truck Underride 101: I. When Will We Tackle Truck Underride?

II. Why Comprehensive Underride Protection? 

Truck Underride 101: II. Why Comprehensive Underride Protection?

III. Cost Benefit Analysis, Underride Rulemaking, and Vision Zero

 Truck Underride 101: Part III. Cost Benefit Analysis, Underride Rulemaking, and Vision Zero

IV. Win/Win

Truck Underride 101: Part IV Win/Win

V. Bipartisan Discussion of Legislative Strategy

Truck Underride 101: Part V. Bipartisan Discussion of Legislative Strategy


Understanding Underride I: Basics of Truck Underride

The problem of truck underride is generally not very well understood. That may be partly due to the fact that we expect a disastrous outcome from a collision between a large truck and a much smaller passenger vehicle.

In fact, one of the biggest problems in a crash between a large truck and a passenger vehicle is that the two vehicles are geometrically mismatched, i.e., the bottom of the truck is higher up than the hood of the passenger vehicle. So the first point of impact is not between the truck and the crush/crumple zone of the car but between the truck and the windshield of the car along with the head and upper body of the occupants of the car. This is called Passenger Compartment Intrusion (PCI) and results in horrific deaths and debilitating injuries for those who might survive.

This holds true all around the truck.  Although there is currently a federal standard for rear underride guards at the back of tractor-trailers, it has been proven by the IIHS to be too weak. There is no federal standard for side guards. And there is no federal standard for protection at the front of trucks, although Europe has had a requirement for Front Underride Protection (FUP) for years. Not to mention that single unit trucks (also known as box trucks) are exempt from federal underride standards. . . and that, although there is a requirement to keep rear guards in like new condition, that is not enforced for the millions of trailers on the road today — so maintenance has not been made a priority.

Hundreds of people die each year in the U.S. because of underride which results in Passenger Compartment Intrusion. If we could prevent underride, many truck crashes would become more survivable. And technology does exist to prevent underride. We just don’t require it to be installed on trucks. As a result, hundreds of people continue to die each year — who could have survived.

These cars collided with the sides of trailers which did not have side guards:

This car collided with the side of a trailer which was equipped with an AngelWing side guard:

Big difference. Night & day. Life & death.

This car collided with the back of a trailer with a weak, ineffective rear underride guard. AnnaLeah and Mary Karth died as a result of PCI:

In contrast, in March 2017. the car below collided with the back of a trailer equipped with an improved, stronger rear guard (provided by Stoughton Trailers as standard on their new trailers at no added weight or cost penalty to their customers). The car is totaled, but there is no PCI;  the driver and passenger walked away with no debilitating injuries:


Understanding Underride V: Front Underride

A panel of experts discuss underride at a Briefing on The Hill, October 12, 2017, to bring greater understanding of the problem and solutions of deadly but preventable truck underride. Keith Friedman, Friedman Research Corporation, discusses Front Underride Protection.

For more information on the STOP Underrides! Act of 2017, go to and/or

Previous Posts on Front Underride Protection (FUP):

  1. People die, on a regular basis, when their car goes under the front of a large truck. Europe has a Front Underride Protection standard for large trucks. Here is some research on this topic to help inform U.S. lawmakers, regulators, and industry leaders on how we can bring this added level of protection to our roads.  .  . Read more here: Front Underride Protection Research; Why don’t we have FUP in the U.S.?
  2. How Far Have We Come In The 50 Years Since Jayne Mansfield’s Death By Truck Underride?
  3. “Crash Analysis of Front UnderRun Protection Device using Finite Element Analysis” research from India
  4. Powerful & Informative Case Made for Underride Guard Improvement by Trucker/Attorney
  5. Why Front Underride or Front Underrun is Important (Deadly yet preventable?)
  6. FRONT Underrun Protection Systems (FUPS) Research; So why does Europe require this & US does not?

Understanding Underride II: From the Insurance Institute for Highway Safety

Here is some basic information on understanding underride from the Insurance Institute for Highway Safety (IIHS):

A panel of experts discuss underride at a Briefing on The Hill, October 12, 2017, to bring greater understanding of the problem and solutions of deadly but preventable truck underride. Matt Brumbelow, a research engineer at the Insurance Institute for Highway Safety (IIHS), discusses the problem of truck underride and the research which IIHS has done to study rear and side underride protection.

For more information on the STOP Underrides! Act of 2017, go to and/or

The Insurance Institute for Highway Safety once again did a fantastic job of hosting the Underride Roundtable. They have now provided us with links to the Second Underride Roundtable held at the IIHS Vehicle Research Center in Ruckersville, Virginia, on August 29, 2017. Here is the agenda, followed by the videos:

Video Links from the Second Underride Roundtable at the IIHS on August 29, 2017



Understanding Underride III: Rear Underride

A panel of experts discuss underride at a Briefing on The Hill, October 12, 2017, to bring greater understanding of the problem and solutions of deadly but preventable truck underride. Malcolm Deighton, engineer with Sapa/Hydro, discusses their aluminum rear underride guard — successfully crash tested at 40 mph.

For more information on the STOP Underrides! Act of 2017, go to and/or

Because our crash involved the failure of the rear underride guard of a truck that we collided with, that was where our initial advocacy efforts were directed. We quickly saw that comprehensive underride protection was important to save countless lives.

Here are some of the things we discovered and did about rear underride:


Understanding Underride IV: Side Underride

A panel of experts discuss underride at a Briefing on The Hill, October 12, 2017, to bring greater understanding of the problem and solutions of deadly but preventable truck underride. Robert Lane, VP of Product Engineering at Wabash National — a trailer manufacturer, discusses their commitment to development of underride protective devices for the prevention of underride deaths and debilitating injuries.

For more information on the STOP Underrides! Act of 2017, go to and/or

Posts and articles on side underride:



Understanding Underride VII: Cost/Benefit Analysis

A panel of experts discuss underride at a Briefing on The Hill, October 12, 2017, to bring greater understanding of the problem and solutions of deadly but preventable truck underride. Jason Levine, Director of the Center for Auto Safety, discusses the flaws in the cost/benefit analysis of truck underride protection.

For more information on the STOP Underrides! Act of 2017, go to and/or

Here are some further thoughts on cost benefit analysis related to underride protection:

  1. “Even if cost-benefit analysis is theoretically a neutral tool. . . it is biased against strong public protections.”Recently, NHTSA announced statistics for 2016 traffic fatalities:
    • 37,461 people killed in crashes on U.S. roadways in 2016
    • Up 5.6% from 2015
    • Tucked in the back of the report, if you look for it, you will see that there were 4,317 fatalities in crashes involving large trucks — up 5.4% from 2015, the highest since 2007. . .
  2. Public Comments on Underrride Rulemaking & Cost/Benefit Analysis: Public Comments Re: Cost/Benefit Analysis in NHTSA Proposed Underride Rulemaking on Rear Guards for Tractor-Trailers & for Single Unit Trucks and       Current NHTSA #Underride Rulemaking (Cost/Benefit Analysis): Summary of Public Comments and

  3. Jerry Karth’s Public Comments on Underride Rulemaking: Comments on the NPRM for Rear Underride Guards on Trailers and Reflections from a bereaved dad on the Underride Roundtable & what that means for rulemaking

  4. Stoughton improved underride guards–standard “at no cost or weight penalty.”
  5. Underride Statistics 

  6. The Future of Trucking: Who pays for the costs of safer roads?

    I thought about all of this, on a recent trip “back home”, as I reflected on the plight of small trucking companies and independent owner-operator truck drivers. Are the costs of owning a company and the pressure to drive many miles creating a situation where they won’t be able to stay in business?

    Frequently, I hear that changes of one kind or another in the trucking industry–in order to improve safety (i.e., reduce crashes, injuries and deaths)–will result in increased costs for the trucking companies. I hear that it will put them out of business.

    Is this true? According to whom and based on what information? If it is true, then does something need to change in the trucking industry itself in order to allow for the beneficial work, which trucking provides, to continue but to also allow for truckers to make a decent living wage–without jeopardizing their health and the safety of travelers on the roads? . . .  Read more here: The Future of Trucking; Who pays for the costs of safer roads?

  7. Whose lives are you going to sacrifice? If decisive action is not taken to end these preventable deaths, then who should we hold responsible? Whose lives are we thereby choosing to sacrifice?

  8. TTMA: Truck Trailer Manufacturers Association Reminds NHTSA Why Side Guards Are Not Cost Effective, May 18, 2016 post:

    Yesterday morning, I checked my email and saw that there was a new Public Comment posted on the Federal Register regarding the Notice of Proposed Rulemaking on Underride Guards.

    I quickly went to the site and saw that the Truck Trailer Manufacturers Association had posted a comment (see their comments in the PDFs below). Apparently our Underride Roundtable two weeks ago at IIHS has spurred them to spell out the steps which have been taken over the years to squash side guards from being mandated and manufactured to prevent smaller passenger vehicles from riding under trucks upon collision with the side of the larger vehicle.



    Their rationaleCost/Benefit Analysis shows that adding side guard to trucks is “not cost-effective”. From this post: Truck Trailer Manufacturers Ass’n “Reminds” NHTSA: Side Guards Are “Not Cost-Effective” Says Who? 

    I am encouraged by the closing paragraph of the TTMA letter to NHTSA:

    TTMA would support the implementation of side guards if they ever become justified and technologically feasible. We continue to support the NHTSA review of Petitioners’ requests and stand ready to partner in the development of justified and feasible designs if they possibly emerge. Jeff Sims, President

  9. How can we possibly justify allowing Death by Underride to continue when solutions exist to prevent it?, As I allow myself to remember the joy and laughter and love and creativity and grumpiness and irritability and silliness of my daughters, AnnaLeah and Mary, I also remember why I am working tirelessly to bring an end to Death by Underride — which snatched AnnaLeah from this earthly life on May 4, 2013, and Mary on May 8, 2013. I was in that horrific truck crash four years ago today. I survived but they did not because of Death by Underride. . .
  10. Mandates take burden off manufacturers. Crash tests in labs better than crash tests occurring in real world., Lou Lombardo has written a thought-provoking opinion piece, Creating a Demand for Crash Testing (CTTI, September 2011). It holds great value in confirming the need for comprehensive underride protection legislation to be introduced and passed in a timely manner. . .
  11. They fought the good fight, they finished the race. . .
  12. Every Day’s A Holiday With Mary; Joyful Memories of Mary
  13. Amazing Grace Goodbye, AnnaLeah & Mary, With Love From Grandpa
  14. Truck Industry Leaders: “Clarity is probably the biggest need we have so we can plan accordingly.”
  15. AnnaLeah Karth. May 15, 1995 – May 4, 2013. Death by Underride.

Understanding Underride VI: Maintenance of Underride Equipment

Recently, I reviewed proposed language for the “Maintenance Section” of the STOP Underrides! legislation [previously known as the Roya, AnnaLeah & Mary Comprehensive Underride Protection Act of 2017]. Working to accurately spell out what was important to include in requirements for proper maintenance of rear underride guards made me realize how imperative it is that the basic problem of underride be better understood.

A true appreciation of the fundamental underride issue could, in fact, lead to a better grasp of what is at stake if an underride guard is not properly maintained. So that is what I hope to foster here. Because this is not a simple matter of keeping a machine functioning so it can continue to drive down the road; it is a matter of maintaining the integrity of a piece of equipment which can, hopefully, prevent sure death or debilitating injury.

Where does maintenance come into the picture? If you have a piece of equipment which is supposed to guard against deadly underride  — if designed in a particular way (and that includes how it is attached to body of the truck), then it would need to be maintained in such a way that it would continue to provide that same strength.

Herein lies the problem. The current rear underride guards on existing trucks might do what they are supposed to in some collisions and successfully prevent underride. However, if the guards (and their attachments to the trucks) are not properly maintained in like-new condition, then their integrity will be compromised and their strength will be weakened. Underride will be even more likely to occur, and people will die as a result.

And this is the reality for the millions of existing large trucks on the road today. As far as I can see, from simple observation when driving on the highways, many of the rear underride guards are not being properly maintained. Of course, this will be important for the newer, stronger guards, too, as they begin to be installed on new trucks or retrofitted to existing trucks.

Read more here: Proper Maintenance of Underride Guards Can Spell the Difference Between L-i-f-e & D-e-a-t-h

A real-life crash between a semi-trailer & 2 cars shows the life & death difference which underride makes.

A real life crash, where two cars collided with a semi-trailer, occurred in the Chicago area on October 16, 2017. One driver died; the other driver survived.

The 38-year-old driver of the Jaguar and the 27-year-old driver of the semi-tractor were each transported to area hospitals with non-life threatening injuries. The driver of the Envoy was pronounced deceased at the scene. 2 Dead, 1 Critically Injured in Aurora Crash Involving Semi

I don’t have proof yet, but it appears to me that the driver who survived may have done so because his car (the white Jaguar) hit the trailer tires, which activated the crush zone of the car and prevented underride ( or Passenger Compartment Intrusion = PCI). The driver of the other car was not so fortunate, the first point of impact was probably in his occupant space.