The use of manned interlocking towers to handle bi-directional operations on low density, single track lines with passing sidings was too costly to be economically feasible and to solve this problem the General Railway Signal company developed Centralized traffic control (CTC) technology. Its first installation in 1927 was on a 40-mile stretch of the New York Central Railroad between Stanley and Berwick Ohio, with the CTC control machine located at Fostoria, Ohio.
High-speed rail is a type of passenger rail transport that operates significantly faster than the normal speed of rail traffic. Specific definitions include 200 km/h (124 mph) and faster - depending on whether the track is upgraded or new - by the European Union and above 90 mph (145 km/h) by the United States Federal Railroad Administration, but there is no single standard, and lower speeds can be required by local constraints. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~