Feasibility Analysis of Urban Transportation Systems with Special Reference to Tunnels.

摘要

Performance-equivalent bus and rail systems were considered under various guideway choices such as dedicated lanes,medians,aerial structures,new rights-of-way,and tunnels. Average per passenger costs were determined for each alternative mode and guideway option. Peak-hour demand was projected for each of the 35largest metropolitan areas based on analysis of 1970journey-to-work tables and assumptions on future growth and distribution of population and employment. The decision to prefer tunnels over other choices is highly sensitive to right-of-way costs (property values) and the relative cost of tunnel excavation. If existing property values and construction costs prevail to 1990, 139miles of tunnels nationwide are projected,while under more favorable conditions,nearly 400miles of tunnels were found to be justified. The likelihood of fulfilling the optimistic condition is discussed.