The youtube channel Curious Droid recently produced a video comparing Japan’s Shinkansen railway the France’s TGV (Train à Grande Vitesse, or “high-speed train”). The video also covers some history of high speed rail and its origins – and the US’s missed opportunity to be a world leader before commercial air travel took over.
Taiwan’s HSR system isn’t mentioned in the video. While not as fast as Japan, France, or other countries’ high speed rail network, it doesn’t need to be (top speeds around 320kmh, usually 290-300). As mentioned in the video, if it takes rail less time to reach a distination, air travel drops considerably because accessing and boarding trains is far quicker and convenient than airports. The direct HSR route (Taipei-Taichung-Kaohsiung) takes just over two hours, far less than the time it would take to get to Songshan Airport in Taipei, board the plane, and fly to Kaohsiung.
Most domestic air travel in Taiwan is to the smaller and popular surrounding islands (Penghu, Green, Orchid, Kinmen) but even that is limited. Ferry service to Green, Orchid and Penghu islands make driving possible.