A common tariff is a standardized schedule of rates, charges, and fees established by a transportation authority or regulatory body that applies to multiple carriers within a specific industry or region. It serves as a reference for determining the costs associated with transportation services and provides transparency and consistency in pricing. Common tariffs ensure fairness and equal treatment among carriers and customers, promoting competition and efficiency in the supply chain. They help streamline the process of rate calculation, billing, and invoicing for the transportation of goods.