At grade rail transit vehicles have historically been considered a major source of conflict, blockage and delay, as well as, collisions with traffic on streets and highways, and continue to increase or create traffic congestion in urban settings. Often promoted as a relief to traffic congestion, the minimal reduction in vehicle trips at grade systems may provide is more than offset by the delays and disruption of traffic at dozens of street crossings and in the reduced capacities of streets occupied by their tracks and stations.
When built in existing street rights of way, as in the East Los Angeles Gold Line extension, a 25-30 foot swath of paved street is separated and dedicated to the two steel rail tracks, with stations occupying even wider areas of the roadway. This generally leaves one through traffic lane in each direction, of what was previously a four-to six-lane street or highway. Introduction of rail facilities on limited sections of streets creates bottlenecks wherever one or more lanes are removed from the right of way. This is clearly the case on the one to two mile sections of First Street and Third Street on which the Each Los Angeles Gold Line rail service has been installed.
Proposals to build a “Regional Connector” of at grade rails in the streets of downtown Los Angeles would create a magnified version of all the congestion problems that rail systems impose on existing streets and highways in urban areas. The construction and operation of such a rail installation and in the already congested downtown streets would create gridlock in the surrounding streets, and most likely impair the operation of the rail system itself; while a proposed LA Streetcar, to be built on four miles of downtown streets, would render the remaining streets of the city dysfunctional.
Such proposals and plans, many of which are actually built, bring the planning and design methods of local transportation agencies into question. Mass transportation planning and development appears, in most U.S. cities, to take place independently from urban and infrastructure planning, and often disrupts existing and surrounding traffic circulation, land uses and municipal services. Furthermore, resources allocated to at grade rail projects, costing $150 million per mile in the case of the East Los Angeles Gold Line Extension, are the least cost effective of any transportation system improvements or congestion relief plans; given the fact that at grade rail appears to cause as much traffic congestion as it may relieve.