Questions and Answers About Vehicle Size and Weight

23 CFR 658.16 Exclusion from length and width determinations

What are some of the more significant types of non-cargo carrying devices excluded from the measurement of the width and/or length of commercial motor vehicles?
Is a 2 1/4-inch step bar on the sides of a vehicle designed to provide a place for someone to stand while loading and/or unloading automobiles excluded from the measurement of the width of automobile transporters?
Are clips, hooks, or other fasteners for fabric sides used to enclose automobile transporters excluded from the measurement of width as tarp hardware?

23 CFR 658.16 Exclusion from length and width determinations

What are some of the more significant types of non-cargo carrying devices excluded from the measurement of the width and/or length of commercial motor vehicles?

Five (5) items are excluded regardless of how far they extend beyond the exterior of vehicles; rear view mirrors, turn signal lamps, handholds for cab entry/egress, splash and spray suppressant devices, and load induced tire bulge. Other excluded devices are (1) all non-property carrying devices or components at the front of a semitrailer or trailer, (2) devices that do not extend more than 3 inches beyond each side or the rear of a vehicle, devices needed for loading or unloading that do not extend more than 24 inches beyond the rear of the vehicle, and (3) aerodynamic devices that do not extend more than 5 feet beyond the rear of a vehicle, provided they have neither the strength, rigidity nor mass to damage a vehicle that strikes a trailer so equipped from the rear and provided also that they do not obscure tail lamps, turn signals, market lamps, identification lamps, or any other required safety features, such as hazardous materials placards or conspicuity markings. For more excluded devices, 23 CFR 658.16 and Appendix D to 23 CFR 658.

Is a 2 1/4-inch step bar on the sides of a vehicle designed to provide a place for someone to stand while loading and/or unloading automobiles excluded from the measurement of the width of automobile transporters?

Yes. It extends less than 3 inches beyond the sides of automobile transporters.

Are clips, hooks, or other fasteners for fabric sides used to enclose automobile transporters excluded from the measurement of width as tarp hardware?

No. A fabric "curtainside" is not the same as a tarp. Nevertheless, clips, hooks, or fasteners are excluded if they do not extend more than 3 inches beyond each side.