Understand Reduced Stopping Distance (RSD) Regulations

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Information to Help You Understand Reduced Stopping Distance (RSD) Regulations
Red Semi Truck

RSD Best Practices

While not required under the FMVSS 121 mandate, it is highly recommended that if your tractor was equipped with RSD friction material as new equipment that when you replace brake shoes, as a component of the overall brake system, you utilize a RSD friction material that maintains the shorter stopping distance to meet FMVSS 121 stopping distance requirements. 

Your Wheelco brake specialist carries brake shoes and kits featuring friction material from the industry’s leading friction suppliers including RSD friction material that was developed by the same R&D teams, utilizes the same technology and is manufactured in the same plants as the OE reduced stopping distance formulations.  

Consult your local Wheelco Heavy Duty brake specialist to select the right product for your application. 

The information is provided as a reference. It is recommended that you:

Old Requirement vs. New Requirement

 1) Reference FMVSS for the specifics of the mandate 
2) Consult with your local Wheelco Heavy Duty brake specialist to select the right product for your application.  

Consult your legal counsel as this post is not intended to give legal advice.


Shorter stopping distances require RSD-compliant friction material as a component of the overall brake system. 

Detailed Information Table
New Requirement vs Old Requirement

Don’t Gamble With Non-Compliant RSD Friction

There is no federal mandate for RSD compliance after the purchase of a new vehicle. Once a tractor is placed into service, the owner can replace the brakes with non-RSD brake lining. This is a practice that is highly discouraged. 

Using brake shoes relined with non-RSD compliant friction can affect a vehicle’s stopping distance performance, leading to longer stopping distances and potentially compromising safety. To avoid such problems, it is recommended that if your truck was built with RSD-compliant friction, you should continue to use an RSD-compliant friction. 

Key Facts

In 2009, the NHSTA amended the Federal Motor Safety Standard on Air Brake Systems (FMVSS No. 121) to improve stopping distances of truck tractors. 

The amended standard requires most new heavy truck tractors to achieve a 30% reduction in stopping distance by two compliance dates – August 1, 2011 and August 1, 2013 (See information below for compliance dates and applicable vehicles).  

  • These heavy truck tractors – approximately 99% of the fleet – are required to stop in no more than 250 feet when loaded to their gross vehicle weight rating (GVWR) and tested at a speed of 60 miles per hour (MPH). 
  • For a small number of very severe tractors, the stopping distance requirement is 310 feet under the same conditions. 
  • All heavy tractors must stop within 235 feet when loaded to their “lightly loaded vehicle weight” (LLVW). 
  • The amended standard addresses only new vehicles and the equipment sold on new vehicles. It does not apply to maintenance procedures once the vehicles are sold to end users. 
  • The required improvement in stopping distance performance is limited to service brakes and does not apply to emergency braking. 
  • The amended standard does not include single unit trucks, trailers, buses, or vehicles produced before the compliance dates. 

Truck Safety

RSD-compliant friction material paired with the enhanced remanufacturing process of CoMan Centers brake shoes provide end users with a total solution. 

Our friction material is sourced from the industry’s leading Tier 1 OE-validated RSD friction suppliers. 

At CoMan Centers we are not only extremely diligent about the materials we uses, but also about the processes we follow. We clean, coin, coat, and cure the highest-quality remanufactured brake shoes in our two U.S. facilities under the strictest standards of quality and environmental control. 

For truck safety and RSD compliance, turn to CoMan Center brake shoes and kits, a trusted resource for heavy duty professionals. 

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