Punktförmige Zugbeeinflussung
After acknowledging the warning signal the train has to stay below the braking curve (German "Bremskurve") - fast trains may travel up to 165 km/h and they must reduce the speed to below 85 km/h after 23 seconds. Note that the operation of high speed trains beyond 165 km/h is not based on visual wayside signals or PZB inductors (using LZB or European Train Control System cab-signalling instead in Germany).
High-speed rail
Germany's first high-speed lines ran north-south, for historical reasons, and later developed east-west after German unification. In the early 1900s, Germany became the first country to run a prototype electric train at speeds in excess of 200 km/h and during the 1930s several steam and Diesel trains achieved revenue speeds of 160 km/h in daily service. The InterCityExperimental briefly held the world speed record for a steel wheel on steel rails vehicle during the 1980s. The InterCityExpress entered revenue service in 1991 and serves purpose built high speed lines (Neubaustrecken) upgraded legacy lines (Ausbaustrecken) and unmodified legacy lines. Lufthansa, Germany's flag carrier, has entered into a codeshare agreement with Deutsche Bahn where ICEs run as "feeder flights" bookable with a Lufthansa flight number under the AIRail program.