This provision is an "objective emission" control. It applies maximum sound levels to various categories of moving vehicles and for several vehicle speeds. It is the backbone of vehicle sound emission regulations. It generally requires a measurement of A-weighted sound level of a moving vehicle at a specific distance from the vehicle path (normally 50 feet). This provision has level restrictions on trucks over 10,000 GVW used locally and in interstate commerce. It also covers motorcycles of two horsepower ratings, mopeds, and all other vehicles on public rights-of-way. The federal government has set maximum levels for heavy trucks used in interstate commerce (40 CFR 202)and for motorcycles (40 CFR 205). Most states and many cities have maximum limits and they generally agree with federal standards where they apply. The most common speed division is 35 mph.