The international definition of high-speed rail embraces new lines with a top speed of at least 250 km/h (155 mph) and existing lines with a top speed of around .\r \r The international definition of high-speed rail embraces new lines with a top speed of at least 250 km/h (155 mph) and existing lines with a top speed of aro.\r \r MegaStructures - UK Super Train (National Geographic Documentary) MegaStructures - UK Super Train MegaStructures (National Geographic Documentary) .\r \r More Megastructures videos on other cannel! JOIN QUIZGROUP PARTNER PROGRAM: .
