High Speed Rail
High-speed rail (HSR) is a type of passenger rail transport that operates significantly faster than the normal speed of rail traffic. Specific definitions include 200 km/h (120 mph) for upgraded track and 250 km/h (160 mph) or faster for new track by the European Union. In Japan Shinkansen lines run at speeds in excess of 260 km/h (160 mph) and are built using standard gauge track with no at-grade crossings. In China, high-speed conventional rail lines operate at top speeds of 350 km/h (220 mph), and one maglev line reaches speeds of 430 km/h (270 mph). http://en.wikipedia.org/wiki/High-speed_rail
What about in the United States?
Amtrak's Acela Express (reaching 150 mph (240 km/h)), Northeast Regional, Keystone Service, and certain MARC Penn Line express trains (the three services reaching 125 mph (201 km/h)) are the only high-speed services in the country according to American standards, but elsewhere in the world "high speed" means services at or above 250 km/h (160 mph)... In 2012, then-Amtrak president Joseph Boardman proposed a plan to build a dedicated high-speed rail line between Washington, D.C. and Boston. He estimated it would cost $151 billion and take more than 25 years to design and build the line. The proposed rail line would allow for top speeds of 220 mph (354 km/h). https://en.wikipedia.org/wiki/High-speed_rail_in_the_United_States
Dec'2017: America’s first bullet train is already a failure and it hasn’t even been built (Dallas/Houston)
Low Population Density, larger distance between major cities?