Pacific Electric Railway 'red car' streetcars stacked in an LA junkyard in 1956.

The General Motors streetcar conspiracy (also known as the Great American streetcar scandal) refers to allegations and convictions in relation to a program by General Motors (GM) and other companies who purchased and then dismantled streetcar and electric train systems in many cities in the United States.

Between 1938 and 1950, National City Lines and Pacific City Lines—with investment from GM,Firestone Tire, Standard Oil of California, Phillips Petroleum, Mack Trucks, and the Federal Engineering Corporation—gained control of electric surface-traction systems in 45 cities including St. Louis,Baltimore, Newark, Los Angeles, Oakland and San Diego, converting many of them to bus operations in that period. Several of the companies involved were convicted in 1949 of conspiracy to monopolizeinterstate commerce in the sale of buses, fuel, and supplies to subsiary companies, but were acquitted of conspiring to monopolize the ownership of these companies.

Some suggest that this program played a key role in the decline of public transit in cities across the United States; notably Edwin J. Quinby, who drew widespread attention to the program in 1946, and then Bradford C. Snell, an assistant attorney for the United States Senate's anti-trust subcommittee, whose controversial 1974 testimony to a Senate inquiry brought the issue to national awareness. Both Quinby and Snell argued that the deliberate destruction of streetcars was part of a larger strategy to push the United States into automobile dependency. Others say that independent economic factors brought about changes in the transit system, including the Great Depression, the Public Utility Holding Company Act of 1935, labor unrest, market forces, rapidly increasing traffic congestion, theGood Roads Movement, urban sprawl, taxation policies that favored private vehicle ownership, and general enthusiasm for the automobile.^[1]

With hindsight a number of more recent studies have questioned that the alleged conspirators had a significant impact on the decline of the streetcar system, rather, they were setting themselves up to take advantage of the decline as it occurred. Guy Span, a noted writer on the subject has suggested that Snell and others fell into simplistic conspiracy theory thinking, bordering on paranoid delusions^{[n 1]} stating:

Clearly, GM waged a war on electric traction. It was indeed an all out assault, but by no means the single reason for the failure of rapid transit. Also, it is just as clear that actions and inactions by government contributed significantly to the elimination of electric traction."^{[n 2]}

In 2010 CBS's Mark Henricks reported:^[2]

There is no question that a GM-controlled entity called National City Lines did buy a number of municipal trolley car systems. And it's beyond doubt that, before too many years went by, those street car operations were closed down. It's also true that GM was convicted in a post-war trial of conspiring to monopolize the market for transportation equipment and supplies sold to local bus companies. What's not true is that the explanation for these events is a nefarious plot to trade private corporate profits for viable public transportation.

Only a small handful of U.S. cities have surviving effective rail-based urban transport systems based on streetcars or trams, including Newark, Philadelphia, San Francisco, Pittsburgh, and Boston; others are re-introducing them. The story has been explored several times in print, film and other media, notably in Who Framed Roger Rabbit, Taken for a Ride and The End of Suburbia.