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What Safety Standards Does FMVSS 121 Impose on Truck and 18 Wheeler Brakes?

There are many Federal Motor Vehicle Safety Standards (FMVSS) set forth in federal law. These safety standards impact nearly all aspects involved in operating a commercial truck like and 18-wheeler, dump truck, or other cargo carrying the vehicle. Safety standards can set forth proper methods of operation or how a truck driver should react to a scenario. Safety standards can also set forth minimum standards that trucking or vehicle equipment must meet or exceed.  

When any vehicle fails to satisfy relevant state or federal safety standards, the risk of a serious accident can be greatly increased. When a large truck weighing tens of thousands of pounds fails to comply with safety standards, then the risk is often even more pronounced. This is due to the fact that, as large vehicles, trucks are often less able to make last-second evasive maneuvers to avoid a crash. Furthermore, when a crash does occur, the immense size and weight of the truck often mean that injuries inflicted are more severe or fatal.  Our truck accident lawyers explain in more detail below.

FMVSS 121 Sets Forth Safety Requirements for Bus, Truck, and Trailer Air Brakes

FMVSS 121 sets forth the vehicles that air brake safety standards apply to. The federal safety standard also sets forth certain performance requirements and characteristics the air brakes must meet or have. The safety standard states that “ The purpose of this standard is to ensure safe braking performance under normal and emergency conditions.” Generally speaking, FMVSS 121 is broadly applicable to commercial trucks and buses. However, there are certain exceptions. Trucks that are exempted from air brake safety rules are set forth in § 571.121 S3. Application and include:

  • Trucks or buses that cannot exceed a speed of 33 miles per hour over a two-mile distance.
  • Trucks or buses that cannot reach a speed of 45 miles per an hour or greater when its unloaded vehicle weight is not less than 95 percent of its gross weight rating and cannot carry passengers other than the driver and operating crew.
  • Certain trucks or buses that qualify as a “heavy hauler trailer.”
  • Trailers that have an unloaded weight that is not less than 95 percent of gross vehicle weight rating.
  • Certain trucks with a gross axle weight rating of 29,000 pounds or greater.

As one might expect, the vast majority of trucks with air brake systems are covered by this rule.

bigstock Red Truck Moving On A Highway 4380639 - What Safety Standards Does FMVSS 121 Impose on Truck and 18 Wheeler Brakes?

Air Brake Systems Must Have Malfunction Detection Features

Per, S5.1.6.1(a), all trucks manufactured after March 1, 1998, are required to have antilock braking systems. Antilock braking systems installed in trucks and commercial vehicles of this type much come with certain error and malfunction detection hardware. Consider that S5.1.6.2(a) requires all covered truck tractors and unit vehicles manufactured after March 1, 1997, and March 1, 1998, respectively, to have a brake malfunction indicator light. Furthermore, the following section also mandates an electrical circuit in certain newer trucks that can tow other vehicles. The safety circuit must be able to transmit brake malfunction signals from the towed vehicle.

FMVSS 121 for Air Brakes Also Sets Forth Stopping Distance Requirements

Stopping distance is one of the most important safety considerations and factors. Vehicles that can stop more quickly are generally more able to avoid serious accidents and the injuries they can cause. By contrast, vehicles that require more distance to come to a halt, require operators to react much sooner. In many cases, vehicle stopping distance is the factor that determines whether an incident will be merely a close call or a collision.

S5.3.1 Stopping distance – trucks and buses, sets forth the stopping distances a commercial vehicle must comply with. It is important to understand that these numbers do not represent maximum stopping distances. Rather, they represent a vehicle that, “shall stop at least once in not more than the distance specified.” Thus, the stopping distances set forth in this safety standard represent something closer to a best case stopping distance scenario.

Federal standards for stopping distances have become more stringent over time. FMVSS 121 first required antilock-equipped truck air brakes in 1975. In the late 1990s, the requirement was extended to include air brake equipped school buses with a GVWR of more than 10,000 pounds. Thus, over time, the standard becomes more rigorous which should hopefully lead to better safety outcomes.

One area that has recently been a focal aspect of the government’s safety efforts is stopping distance. IN 2009, the federal government first announced and published its intention to improve the performance of air brake equipped vehicles. The government has focused on increasing brake performance as evidenced by decreasing vehicle stopping distances.

Phase I of the program went into effect in 2011. This phase impacted tractors grossing up to 59,600 pounds. These vehicles were selected for the first phase of the program for several reasons. First, tractors of this type comprise the majority of heavy, commercial trucks on the road, and thus, the vehicles that are typically involved in accidents. Under Phase I, a loaded tractor was required to stop within 250 feet at 60 miles per an hour. In August 2013, the standard began to apply to more vehicles including trucks with just 2 axles and trucks with four or more axles. Furthermore, trucks with three axles but with a GVWR greater than 59,600 pounds were also included under the standard. Under the 2013 Phase II standard, most loaded trucks are required to stop within 250 feet. Certain trucks with four or more axles or extremely high GVWR have a required stopping distance of 310 feet.

truck accident lawyers - What Safety Standards Does FMVSS 121 Impose on Truck and 18 Wheeler Brakes?

Contact an Experienced Commercial Truck Accident Lawyer

When vehicles fail to meet or exceed the safety requirements required by the federal government, all motorists face a greater risk of an accident. In the case of vehicle stopping distances, many trucking firms do not necessarily intend to violate safety standards or place unsafe vehicles on the highway. Rather, concerns about the bottom line may result in deferred maintenance. Over time, putting off repair work may mean that brakes and other vehicle equipment do not function optimally – or at all.

If you or a loved one have suffered a serious injury due to a truck that did not or could not stop in time, the truck accident injury lawyers of Reiff Law Firm’s The Truck Accident Team may be able to help. For more than 35 years, the lawyers of Reiff Law Firm’s The Truck Accident Team have sought justice when trucking company negligence or carelessness by truckers has caused serious injuries for truck accident victims. To schedule a free and confidential initial legal consultation, call (215) 246-9000 today.

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