Understanding safe commercial vehicle design



Published in January 2024 Fleet Affiliation.

One of the most important aspects of commercial vehicle design is to ensure the safety of the final product, as spec writers and fleet professionals have an obligation to provide safe vehicles. While it may appear to be a straightforward task, the vocational truck segment introduces a level of complexity. These vehicles are manufactured in multiple stages, necessitating a comprehensive understanding of how all components integrate and function together.

A commonly overlooked pitfall, which often begins during the design phase, is vehicle overloading. Indeed, weight is one of the most limiting factors when designing multi-stage vehicles. Many times, spec writers look at the final product and the gross vehicle weight rating (GVWR), often failing to take into account individual components such as axles, springs, tires, etc. If any component rating is exceeded, the vehicle is overloaded regardless of GVWR.

Impacts of upfitting
Vehicle upfitting is a standard practice in the vocational market, but the presence of mandated safety systems and components can affect compliance. Vehicle manufacturers often provide documentation for incomplete vehicles, as well as guidance with body builder books. While final vehicle certification falls with the upfitter or final-stage manufacturer, it’s important to understand general requirements and avoid designing vehicles with components that may bring them out of compliance.

Understanding the regulatory bodies
Several regulatory bodies can impact vehicle design. The National Highway Traffic Safety Administration (NHTSA) oversees motor vehicle safety and sets Federal Motor Vehicle Safety Standards (FMVSS). Additionally, regulatory bodies such as the Occupational Safety and Health Administration (OSHA) and the Mine Safety and Health Administration (MSHA) may introduce other regulations based on the industry served. Individual state and local regulations add yet another layer of complexity. For example, utility fleets commonly place cone holders on the front of vehicles, but several states have regulations regarding front protrusion. While it may seem an insignificant detail, it should be taken into account during the design process.

Environmental understanding
Another important factor in the design process is environmental awareness and understanding. It’s critical to know how the vehicle will be used, including all intended purposes and operating environments. For example, on service vehicles that carry heavy tools, designing compartments close to the ground may be beneficial for ease of access. Another example is verticle versus horizontal exhaust. Vehicles designed for extended power export, such as PTO operation, may be suitable for verticle exhaust to avoid operator exposure to exhaust fumes. While such changes may not impact vehicle function, they can make a significant difference to the operator.

In the end, it’s important to fully understand how the trucks will actually be used. Taking the time to make field observations can help you design regulatory-compliant vehicles while improving safety and lowering operating costs.

Learning more
Work Truck Week® 2024, scheduled March 5–8 in Indianapolis, Indiana, features unmatched opportunities for fleet professionals. North America’s largest work truck event offers three days of industry-specific educational programs and Chassis Update Sessions; an expansive exhibit floor displaying the most innovative commercial vehicles, equipment and technology from 500+ companies; multiple networking opportunities; a two-day Ride & Drive; and Green Truck Summit, the industry’s leading advanced vehicle and fuel technology conference. Register through Feb. 8 to take advantage of advance pricing.