Soon the new technology of the trolley car was being applied to elevated railways as well, allowing large cities such as New York, Chicago, and Boston to continue to grow rapidly. As the century-turned, the boom was on. The electric railway industry mushroomed in size until by 1920 it was the fifth largest industry in the United States. In 1890, street railways carried two billion passengers; by 1902, the number had risen to five billion, more than several times the number carried on the nation's steam railroads.
Another variation, the interurban electric railway, competed directly with steam railroads for the first two decades of the twentieth century. These interurbans, as they were called, followed major streets in urban areas, then set out -- often paralleling existing railroads -- across the countryside to serve nearby towns.
Although the trip often was slower than the paralleling steam road's service, it was offered more frequently. Thus the interurban grew to its biggest proportion in regions that had scattered towns and suburbs surrounding a major metropolitan core -- such as Los Angeles and Indianapolis -- or had concentrated development along a population corridor, such as those connecting Chicago-Milwaukee, Cincinnati-Day ton, or Oakland-Sacramento-Chico (California).
The interurban turned out to be little more than a transitional step between sole reliance on the steam railroad for intercity transit and almost sole reliance on the personal automobile (which was still several decades in the future). Although a few interurban systems actually prospered -- usually due to the fact that they also carried freight, in direct competition with steam railroads -- few industries have grown so rapidly or declined so quickly, and no industry of its size ever had a more dismal financial record.
Not surprisingly, the interurbans began their precipitous decline on the eve of World War I -- as the automobile was becoming available to all -- and during the Depression the industry was virtually annihilated.