A motor vehicle designed to transport how many passengers, including the driver, is considered a commercial motor vehicle?

A motor vehicle designed to transport 16 or more passengers, including the driver, is classified as a commercial motor vehicle according to the Federal Motor Carrier Safety Administration (FMCSA) regulations. This classification takes into account both passenger vehicles and buses used for public transport or similar purposes. Vehicles designed to carry fewer than 16 passengers, which includes the driver, do not fall under this commercial vehicle category, hence the need for specific regulations and licensing does not apply. Therefore, the selection of 16 as the threshold reflects these regulatory standards, making it the accurate answer in this context.