Countries with operational high-speed rail networks. While the International Union of Railways defines high-speed rail as public transport by rail at speeds of at least 200 km/h (124 mph) for upgraded tracks and 250 km/h (155 mph) or faster for new tracks, this quizz takes into account all the systems and lines that support speeds over 200 km/h (120 mph) regardless of their statuses of upgraded or newly built. Countries in yellow do NOT run trains over 250 km/h (124 mph).