High speed rail systems can have substantial impacts on other transport modes, even freight transport systems. One of the most apparent is on air transportation services between cities along the high speed rail corridor, particularly the most distant ones. High speed rail is able to compete successfully with short to medium distance air transport services as it conveys the advantage of servicing downtown areas and has much lower terminal time, mainly because of less security constraints. For city pairs closer than 500 km, the introduction of high speed rail services will in the majority of cases remove commercial air services as they cease to be competitive. Flights on routes that are over 1,500 km are usually little impacted. This can have a very important impact on air transportation since the world's most active air routes are all short hauls of less than 1,000 km.Another emerging trend concerns a complementarity between HSR and air transportation, which involves cooperation between a national air and rail carrier. For instance, Lufthansa and Deutsche Bahn as well as Air France and SNCF offer single fares and tickets for selected routes where a high speed rail segment is offered instead of a flight. There is thus a balance between competition and complementarity for HSR and air transportation services, particularly when there is congestion in the air transport system. In this situation the complementarity may help release airport gate slots that can be used to support more revenue generating (longer distance) flights or to reduce congestion.Rail stations with high speed rail services are also increasingly becoming transport hubs with the associated demands on urban transport systems, particularly public transit. Regarding high speed rail stations, two dynamics have emerged: