Tag Archives: commercial trucking

Weighing the Benefits of Weigh Stations

By Amy Terrone

Have you ever driven by a weigh station on the side of the highway and wondered what happens to all those trucks that enter that parallel roadway?

And why do some trucks get to whiz by, while others crawl into the station?

NTSB Highway investigators at a weigh station in Boise, ID
NTSB Highway Investigators Mike Fox (L) and Dave Pereira (R) talk with a CMV officer at a Boise weigh station.

I learned the answer to these questions recently when I joined NTSB highway investigators for a tour of one of Idaho’s busiest weigh stations. This visit was sponsored by the Idaho State Police (ISP) commercial motor vehicle enforcement team, which works closely with the Idaho Transportation Department, the lead agency for size and weight and encompasses the Port of Entry Inspectors and weigh stations. The ISP is the lead agency for safety; they inspect commercial trucks for safety violations and put them out of service if they aren’t complying with state and federal regulations.

Several NTSB Highway Safety Investigators and I were attending the Commercial Vehicle Safety Alliance (CVSA) annual conference in Boise, Idaho, last week when the ISP presented us with an opportunity to view the live operations at one of their weigh stations. (The outgoing CVSA president is an ISP major.)

The CVSA conference brings together commercial vehicle truck inspectors (mainly law enforcement), truck and motorcoach fleet owners, regulatory agencies, and other commercial motor vehicle safety advocates around the nation to discuss the latest safety innovations, regulatory requirements, and inspection tactics for commercial motor vehicles.

It turns out that trucks which have been pre-screened and which have a current good safety record, similar to the TSA pre-check for airline passengers, can skip specific roadside weigh stations. Idaho uses a bypass system called NORPASS. With about 30 commercial motor vehicle enforcement officers covering the whole state of Idaho, the goal is not to spend time focusing on the truck drivers/operators who are making the commitment to operate safely and follow regulations.

Those drivers who don’t participate in NORPASS must come in to be…yes, weighed. If the loaded truck weighs more than 80,000 pounds, give or take, then the driver may be asked to pull over and unload.

Why do we care about weight? Because too much weight can tear up the roadway, creating a safety hazard for all drivers. Plus — and the NTSB has seen this in our investigations — overweight trucks can cause additional damage if involved in crashes.

But other information can come out of these weigh station stops.

The weigh station manager showed us how information pops up on their screens as trucks come through that indicates the trucks weight, height, safety score and paper credentials, i.e. registration, taxes, and any out-of-service violations or suspensions. 

ISP commercial motor vehicle officers onsite may also conduct a random inspection. If such an inspection uncovers serious violations, then the truck, the driver, or both may be placed “out of service” — meaning they can’t continue to operate until the unsafe condition has been corrected.

What happens if a truck without the NORPASS transponder runs the station? Commercial motor vehicle enforcement officers chase them down. 

The station manager shows NTSB staff their weight-tracking system.
The station manager shows NTSB staff their weight-tracking system.

I was impressed by how smoothly the operation ran at the Boise weigh station. There was a separate lane for “regulars” so to speak who traverse the station daily or at least multiple times weekly. A person sits behind the window and watches every truck going through, carefully noting the license plate, VIN, and other identifying vehicle information.

With “Strengthening Commercial Trucking Safety” on the NTSB’s Most Wanted List of safety critical improvements, it was important for NTSB to be at the CVSA conference and tour sites such as this roadside weigh station. More than 4,000 people die each year as a result of truck crashes, and truck crashes have been on the rise. Our visit to the ISP weigh station gave us a first-hand look at the work being done to combat this truck safety problem and how information obtained from them can provide us with valuable information in our crash investigations.

Like many of us on the roads, I didn’t know all that was happening inside these non-descript buildings on the side of the road. The men and women who staff them are our eyes and ears on the roads – looking for bad trucks and bad drivers. And, ultimately, the work they do is a critical component of the highway safety process that will help reduce crashes, along with injuries and fatalities on our roadways.

Amy Terrone is a Writer-Editor in the NTSB Office of Highway Safety.

Commercial Trucks Need Collision Warning and Braking Technology

graphic of commercial truck collistion warning By Christopher Hart

Last week, host Mark Willis of Road Dog Trucking News interviewed me about a recent NTSB report on collision avoidance systems (CAS). He wanted to share with his listeners the benefits of technology that not only warns a driver of an imminent crash into something ahead, but also stops the vehicle if the driver doesn’t.

The show’s call-in format gave me the opportunity to talk directly to truck drivers who would benefit from this technology—and to listen to them as well. (The host frequently reminded drivers not to call in while driving.) It was a conversation with an audience whose business is on the highway, hour after hour, week after week, and whose business is crucial to our country’s economy.

Without a doubt, commercial truck drivers are aware that heavy trucks require longer stopping distances. That is why collision mitigation can be so beneficial for commercial vehicles.

For trucks, a complete CAS includes collision warning, which warns drivers about an imminent obstacle ahead, and autonomous emergency braking (AEB) to stop the truck if the driver does not heed the warning.

image of the report cover
The NTSB released its special investigation report, titled “The Use of Forward Collision Avoidance Systems to Prevent and Mitigate Rear-End Crashes” in early June.

Some skeptical callers said that AEB would destabilize the vehicle by stopping it abruptly. That concern is why our June report recognized that AEB should be paired with electronic stability control (ESC), something that many commercial trucking fleets recognize. ESC would be essential, as it would prevent jack-knifing and loss of control during AEB applications.

Last month, following our report, the National Highway Traffic Safety Administration (NHTSA) issued a final ruling mandating ESC on every new truck tractor weighing 26,000 pounds or more within the next four years.

The commercial vehicle industry estimates that about 10 percent of new truck-tractors are already equipped with collision warning and AEB systems. Some companies are already transitioning their fleets to CAS-equipped truck-tractors, not only to improve safety and save lives, but also to save money (e.g., workers comp and numerous other costs resulting from a crash).

The NTSB has been pushing for crash mitigation technology for commercial vehicles for two decades. We issued our first recommendations on testing these technologies in 1995.

In 2001, we urged NHTSA to develop adaptive cruise control and collision warning system performance standards, and then to use those standards to mandate standard collision warning on all new commercial vehicles. NHTSA has yet to satisfy these recommendations, although its new ESC rule is a good and necessary first step.

The recommendations we released in our latest report would help bring CAS technology to members of the Road Dog audience. The NTSB called for truck-tractor and single-unit truck manufacturers to immediately install, at a minimum, the collision warning component of CAS. Further, we asked manufacturers to add AEB systems once NHTSA completes performance standards for those systems.

Along with our 2015 report, we issued a safety alert to fleet owners and consumers of passenger vehicles. This alert advises purchasers about the safety benefits of CAS, and urges them to request vehicles with AEB and collision warning. And if truckers don’t see CAS in their trucks, they should ask their companies for it because their lives and the lives of the traveling public could depend on it.


Christopher Hart is Chairman of the National Transportation Safety Board.

ESC for Heaviest Trucks and Buses: A Great First Step Toward Saving Lives

Photo of Indianapolis, IN, rollover crash of combination vehicle.
Indianapolis, IN, rollover crash of combination vehicle.

By Robert Molloy

The NTSB has long urged that trucks and buses be equipped with electronic stability control (ESC) to help prevent and mitigate crashes. ESC automatically helps drivers maintain directional control when they cannot steer and brake quickly enough on their own. We are pleased that the National Highway Traffic Safety Administration (NHTSA) released a final rule earlier this month—FMVSS No. 136that will help drivers of large vehicles do just that.

The new rule requires ESC systems on heavy trucks and large buses with weight ratings over 26,000 pounds, and NHTSA is beginning the process of expanding the requirement to include medium-sized vehicles between 10,000 and 26,000 pounds.

The rule covers vehicles such as the truck-tractor cargo tank semitrailer involved in the 2009 Indianapolis, Indiana, crash.

In that crash, the driver of the combination unit, which was loaded with 9,000 gallons of liquefied petroleum gas, went through a guardrail and collided with the support structure of an interstate overpass. The truck driver had been negotiating a left curve in the right lane on the connection ramp, which consisted of two southbound lanes, when the combination unit began to encroach upon the left lane, occupied by a passenger car. The truck driver responded by oversteering clockwise, causing the combination unit to veer to the right and travel onto the paved right shoulder. The driver’s excessive, rapid, evasive steering caused the cargo tank semitrailer to roll over and separate from the truck-tractor. A large explosion followed the crash, and five people were seriously injured.

The NTSB determined that the rollover might have been prevented had the truck been equipped with an ESC system. As a result of this investigation, the NTSB issued two recommendations requiring ESC on all commercial vehicles.

The new rule is a good first step. Applying the rule to all vehicles over 10,000 pounds is difficult, as hydraulic ESC systems for commercial vehicles are just beginning to be deployed. However, until ESC is expanded to cover commercial vehicles below 26,000 pounds, we may still see crashes such as the one NTSB investigated in Dolan Springs, Arizona. In that crash, a medium-size tour bus with a weight rating of 19,500 pounds was traveling on a four-lane divided highway when it started moving to the left and out of its lane at about 70 mph. The driver steered sharply back to the right, crossing both lanes and entering the right shoulder. The driver overcorrected to the left, again crossing both lanes. The bus entered a median and rolled all the way over before coming to rest on its side. As a result, seven passengers died and nine others were injured.

As vehicle safety technologies continue to be developed, ESC becomes all the more important. ESC is a necessary component of, and serves as a platform for, other life-saving technologies such as collision avoidance systems that include autonomous emergency braking (AEB). According to our Special Investigation Report (SIR) on The Use of Forward CAS to Prevent and Mitigate Rear-End Crashes, the full benefits of AEB for commercial vehicles can be achieved only when such a braking system is installed on vehicles also equipped with ESC. Equipping commercial vehicles with both AEB and ESC would be an effective countermeasure against rear-end collisions.

NHTSA estimates the new ESC rule—which will be rolled out in stages over the next four years—will prevent as many as 1,759 crashes, 649 injuries, and 49 deaths each year. When it becomes expanded to smaller vehicles, even more lives will be saved.

Robert Molloy, PhD, is the Acting Director of the NTSB’s Office of Highway Safety.