High-speed rail in Switzerland
, Switzerland has no high-speed trains of its own yet. French TGV (TGV Lyria) and German ICE lines extend into Switzerland, but given the dense rail traffic, short distances between Swiss cities (because of the country's small size) and the often difficult terrain, they do not attain speeds higher than 200 km/h (ICE3) or 160 km/h (TGV, ICE1, ICE2). The fastest Swiss trains are the ICN tilting trains, operated by the Swiss Federal Railways since May 2000. They can reach higher speeds than conventional trains on the curve-intensive Swiss network, however the top speed of 200 km/h can only be reached on high-speed lines. The former Cisalpino consortium owned by the Swiss Federal Railways and Trenitalia used Pendolino tilting trains on two of its international lines. These trains are now operated by the Swiss Federal Railways and Trenitalia.
Passenger rail terminology
There is no globally accepted standard separating high-speed rail from conventional railroads; however a number of widely accepted variables have been acknowledged by the industry in recent years. Generally, high-speed rail is defined as having a top speed in regular use of over . Although almost every form of high-speed rail is electrically driven via overhead lines, this is not necessarily a defining aspect and other forms of propulsion, such as diesel locomotives, may be used. A definitive aspect is the use of continuous welded rail which reduces track vibrations and discrepancies between rail segments enough to allow trains to pass at speeds in excess of . Track radius will often be the ultimate limiting factor in a train's speed, with passenger discomfort often more imminent than the danger of derailment. Depending on design speed, banking and the forces deemed acceptable to the passengers, curves often exceed a 5 kilometer radius. Tilting trains have been developed for achieving greater comfort for passengers, so higher speeds are possible on curvy tracks. Although a few exceptions exist, zero grade crossings is a policy adopted almost worldwide, with advanced switches utilizing very low entry and frog angles. Magnetic levitation trains fall under the category of high-speed rail due to their association with track oriented vehicles; however their inability to operate on conventional railroads often leads to their classification in a separate category.