A more thorough explanation:

A Port Authority is a government agency that oversees the operations and regulations of a port or airport. They are responsible for maintaining and improving the infrastructure of transportation systems such as bridges, tollways, and public transportation.

For example, the Port Authority of New York and New Jersey is responsible for managing the ports, airports, and transportation systems in the New York City metropolitan area. They oversee the operations of the Port of New York and New Jersey, John F. Kennedy International Airport, LaGuardia Airport, and several bridges and tunnels that connect New York and New Jersey.

Another example is the Port of Los Angeles, which is managed by the Port of Los Angeles Port Authority. They oversee the operations of the port, which is one of the busiest in the world, and work to improve the infrastructure to accommodate the growing demand for international trade.

These examples illustrate how Port Authorities are responsible for managing and regulating transportation systems to ensure the safe and efficient movement of goods and people. They work to improve the infrastructure to meet the needs of the growing population and economy.