German ICE 3
High-speed rail (HSR) is a type of passenger rail transport that operates significantly faster than the normal speed of rail traffic. Specific definitions by the European Union include 200 km/h (124 mph) for upgraded track and 250 km/h (155 mph) or faster for new track; while in the United States, the U.S. Department of Transportation's reasonably expected to reach sustained speeds of more than 125 mph (201 km/h), although the Federal Railroad Administration uses a definition of above 110 mph (177 km/h). In Japan, Shinkansen lines run at speeds of up to 300 km/h (186 mph) and are built using standard gauge track with no at-grade crossings. China high-speed conventional rail lines currently holds the world's fastest commercial top speed of 350 km/h (217 mph)
High-speed trains are used mostly for long-haul service and most systems are in Western Europe and East Asia. Due to their heightened speeds, route alignments for high-speed rail tend to be steeper grades and broader curves compared to conventional railways. Their high kinetic energy translates to higher horsepower-to-ton ratios (20 hp/ton); this allows trains to accelerate and maintain higher speeds and negotiate steep grades as momentum builds up and recovered in downgrades (reducing cut, fill, and tunneling requirements). Since lateral forces act on curves, curvatures are designed with the highest possible radius. All these features are dramatically different from freight operations, thus justifying dedicated, exclusive high-speed rail tracks if it is economically feasible.
Jane Jacobs, (May 4, 1916 – April 25, 2006) was an American-Canadian writer and activist with primary interest in communities and urban planning and decay. She is best known for The Death and Life of Great American Cities (1961), a powerful critique of the urban renewal policies of the 1950s in the United States. The book has been credited with reaching beyond planning issues to influence the spirit of the times.
Along with her well-known printed works, Jacobs is equally well-known for organizing grassroots efforts to block urban-renewal projects that would have destroyed local neighborhoods. She was instrumental in the eventual cancellation of the Lower Manhattan Expressway, and after moving to Canada in 1968, equally influential in canceling the Spadina Expressway and the associated network of highways under construction. Jane Jacobs spent her life studying cities. Her books include among others: The Death and Life of Great American Cities, The Economy of Cities, Cities and the Wealth of Nations, The Question of Separatism: Quebec and the Struggle over Sovereignty.
Perhaps her single-most influential book and possibly the most influential American book on urban planning and cities, The Death and Life of Great American Cities is a strong critique of the urban renewal policies of the 1950s, which, she claimed, destroyed communities and created isolated, unnatural urban spaces and widely read by both planning professionals and the general public. Jacobs advocated the abolition of zoning laws and restoration of free markets in land, which would result in dense, mixed-use neighborhoods and frequently cited New York City's Greenwich Village as an example of a vibrant urban community. Beyond the practical lessons in city design and planning that Death and Life offers, the theoretical underpinnings of the work challenge the modern development mindset. Jane Jacobs defends her positions with common sense and undeniable anecdote.
The Economy of Cities is a book that asserts cities are the primary drivers of economic development. Jacobs' main argument is that explosive economic growth derives from urban import replacement. Import replacement is when a city begins to locally produce goods which it formerly imported (e.g., Tokyo bicycle factories replacing Tokyo bicycle importers in the 1800s). Jacobs claims that import replacement builds up local infrastructure, skills, and production. Jacobs also claims that the increased produce is exported to other cities, giving those other cities a new opportunity to engage in import replacement, thus producing a positive cycle of growth. In the second part of the book, Jacobs argues that cities preceded agriculture. She argues that in cities trade in wild animals and grains allowed for the initial division of labor necessary for the discovery of husbandry and agriculture; these discoveries then moved out of the city due to land competition.