There are crucial differences in the choice of mass transit technology that affect the patterns of land uses and the arrangement of buildings and public spaces around transit stations and corridors. Characteristically, commuter-rail transit stations need to be 2 to 5 miles apart to allow long acceleration and deceleration times required by diesel powered locomotives. Tracks are generally separated from other urban uses except at stations, where some limited integration with streets and pedestrians is permissible. Conventional commuter rail suffers from several of the same problems as heavy rail systems in terms of difficulties with pedestrian friendly environments along the transit corridor. At the stations, however, because there are no electrical rails or wires a greater degree of integration with vehicles and pedestrians can be achieved. The Metropolitan Atlanta Rapid Transit Authority (MARTA) in Georgia is an example of the type of heavy rail transit system. The heavy rail system is one of high capacity and high speed necessitated by the ridership demand to travel relatively long distances at greater speeds than is typical of the light rail and bus systems. By design the heavy rail system requires greater attention and emphasis on pedestrian environment in and around the transit station rather than along the transit corridors because of essential grade separation for operational and safety reasons. Source/Reference: ARC, A.