Thứ Ba, 3 tháng 11, 2009

Urban Transportation Systems

Urban Transportation Systems
You can get there from here. ...Urban Transportation Systems: Choices for Communities (2003; McGraw-Hill; 840 pages; $99.95) offers a thorough and balanced look at the pros and cons of 16 different modes of moving people around in cities, from walking to aerial tramways.
Author Sigurd Grava, FAICP, who teaches planning at Columbia University and is vice-president and technical director of planning at Parsons Brinckerhoff Quade and Douglas, takes an optimistic long view: "There were periods in urban history when only a single transportation mode was reasonably available--horses, steam locomotives, or streetcars--and, thus, evaluation and selection were not much of an issue." Today, in contrast, there are many options, and we have the opportunity--and difficulty--of choosing appropriate modes from an unprecedented number of possibilities. The book is arranged by mode. Separate chapters deal with walking, bicycles, motorcycles and scooters, automobiles (the longest chapter with more than 100 pages), paratransit, taxis, buses, bus rapid transit, trolleybuses, streetcars and light rail, monorails, heavy rail, commuter rail, automated guideway transit, waterborne modes, special modes, and intermodal terminals. "The fundamental premise of this review," writes Grava, "is that all modes are good, but only in their proper place." The author makes no attempt to discuss the "urban transportation problem" or comprehensive planning in general, but he does laydown some general criteria. Each mode gets a thorough listing of its pros ("reasons to support") and cons ("reasons to exercise caution") and its cost. The treatment is semi-technical, more detailed than is likely to appeal to the general public but not at the level of mechanical or traffic engineering. The author negotiates the many controversial areas of this subject with aplomb, including whether bicycle lanes are a good idea and what costs auto users do and do not pay. "Gasoline taxes and user charges cover less than two-thirds of all the tangible costs," he writes, "if, besides the construction and maintenance of roadways, highway patrols, traffic management, emergency response, and police investigations are also included," and even less if parking, accident costs, and pollution are added. On the other hand, "if the overwhelming part of the society is the beneficiary of this assistance, then they are simply shifting their own resources from one budget class to another, and they have the right to do that. And, if a rigorous cost-benefit analysis were to be demanded, the American public would easily see sufficient benefits in this situation to justify the costs."

Download : pdf /12.5 MB/
or rzpmd5

Không có nhận xét nào:

Đăng nhận xét