While the majority of at grade rail tracks and stations are located in public streets or within other publicly owned right of way corridors, the surrounding environments of existing residential neighborhoods, commercial districts, schools, libraries, parks, open spaces, sidewalks and other pedestrian areas through which they pass are subjected to all of the impacts of construction and operation of at grade rail systems. It is commonly necessary to contain or mitigate the impacts of noise, dust, dirt, hazards and the disruptive effects of massive vehicles and trains passing through a variety of human activity settings.
Mitigation measures typically include construction of sound walls along the rail corridor to minimize the significant noise impacts of the system, and may employ rubberized roadbed materials to reduce vibrations associated with steel wheel, steel rail equipment and rolling stock of the system. Adding additional acoustical insulation to nearby existing occupied buildings and homes may be required in order that noise mitigation measures are implemented. Noise mitigation measures are limited at road crossings, where sounds of passing rail vehicles and related safety equipment cannot be blocked with sound walls. Safety devices including loud bells and warning horns contribute additional noise pollution at all crossing points along rail routes. These effects often extend 1,000 feet or more from the mass transit systems, depending on the shape and nature of built and natural environments surrounding tracks and equipment.
In addition to the direct environmental impacts resulting from at grade rail systems, the impact of idling automobile and truck engines stopped at the crossings should be considered among the effects of at grade rail developments. The aggregate and continuous impacts of at grade rail operations on neighborhoods and other human activity settings and networks may outweigh the benefits of traffic congestion relief and improved access to destinations and stations that the system was designed to provide. This comparison and weighing of broader benefits of rail system development against the more immediate and localized impacts of construction and operation can lead to more enlightened decision making with regard to the location and type of systems that transportation authorities develop.