Impacts of elevated rail system development on local and extended environmental settings occur in the construction and operational phases of system implementation. While environmental impacts of construction and development of elevated rail systems are generally limited to the immediate vicinity and property of the construction projects, for the duration of the construction activity, the impacts of system operation range throughout the length of the system for the lifetime of the system’s operation.
Demolition and clearing of elevated rail right of way property is generally the most extensive of all mass transportation types, and the structures erected to support elevated rails ten to be the largest and most visible of transportation facilities. The resulting impacts of short-term construction, and the long-term, seemingly permanent impacts of massive elevated structures and the train operations they support are significant, and only partially mitigable. Poorly designed elevated structures can have enduring negative impacts on neighborhood and community settings: Or can blight the image of a city, as did San Francisco’s Embarcadero Freeway, until the multi-level freeway was destroyed in an earthquake. Noise and other intrusive effects of steel rail trains operating in prominent, elevated locations are subject to partial mitigation, at significant expense, but can not by completely buffered from the surrounding environments through which they pass.
Even when proposed as the only feasible solution to transportation problems or demand, elevated rail structures should not be recommended, when monorail systems and technology could provide the same level of service with smaller building and land use footprints, significantly less massive infrastructure, and a small fraction of the environmental impacts of elevated steel-wheeled, steel rail train systems.