As a densely populated country in a central location in Europe and with a developed economy, Germany has a dense transport infrastructure. One of the first limited-access highway systems in the world to have been built, the extensive German Autobahn network has no general speed limit for light vehicles (although there are speed limits in many sections today, and there is an 80 km/h (50 mph) limit for trucks). The country's most important waterway is the river Rhine, and largest port is that of Hamburg. Frankfurt Airport is a major international airport and European transport hub. Air travel is used for greater distances within Germany but faces competition from the state-owned Deutsche Bahn's rail network. High-speed trains called ICE connect cities for passenger travel with speeds up to 3