After the breakthrough of electric railroads, it was clearly the infrastructure – especially the cost of it – which hampered the introduction of high-speed rail. Several disasters happened – derailments, head-on collisions on single-track lines, collisions with road traffic at grade crossings, etc. The physical laws were well-known, i.e. if the speed was doubled, the curve radius should be quadrupled; the same was true for the acceleration and braking distances.
In 1891 the engineer Károly Zipernowsky proposed a high-speed line Vienna–Budapest, bound for electric railcars at 250 km/h (160 mph). In 1893 Dr. Wellington Adams proposed an air-line from Chicago to St. Louis of 252 miles (406 km). At a speed of only 160 km/h (99 mph), he was more modest than Zipernowsky – and more realistic, according to General Electric.
Alexander C. Miller had greater ambitions. In 1906, he launched the Chicago-New York Electric Air Line Railroad project to reduce the running time between the two big cities to ten hours by using electric 160 km/h (99 mph) locomotives.

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