Greater Los Angeles has a complex multimodal transportation infrastructure, which serves as a regional, national and international hub for passenger and freight traffic. The transportation system of Greater Los Angeles includes the United States' largest port complex, seven commuter rail lines, Amtrak service, a subway system within the city of Los Angeles, and numerous highways. Los Angeles is integrated into the Interstate Highway System by Interstate 5, Interstate 10, and Interstate 15, along with numerous auxiliary highways and state routes. Bus service is also included locally within the area by numerous local government agencies. Subways and light commuter rail lines are present within Los Angeles proper, allowing mass transportation within the city. Commuter railroads are run by Met