In the July issue of In Service Online, we emphasized the importance of understanding vehicle weight ratings. One of our readers points out that it is equally important to understand state and local weight laws.

Frank Moffat, fire apparatus program supervisor in Redmond, Wash., notes that different states often have different weight laws regarding fire and emergency vehicles. Some laws apply to specific types of vehicles, but not to others — for example, the law in Washington applies to fire suppression vehicles, but not to hazmat response units.

Specific state weight laws for fire and emergency vehicles may be based on the tire width, tire footprint area, axle spacing, date a vehicle was placed in service, or whether a vehicle is operated by a governmental fire agency or a private fire brigade. Many other factors can apply as well, depending on the state.

Overall common-sense limitations also apply, and some are written into state weight laws. Two obvious limitations include not crossing a bridge with a vehicle that exceeds the posted weight limit and not loading a tire or other component beyond the manufacturer’s published load rating.