undreds stood in line to enter the globe-like "Scenic Lines of the World" railroad exhibit at the 1915 Panama-Pacific International Exposition in San Francisco. Featuring a relief map of train routes on the exterior, and model locomotives on the interior, the booth - nearly 25 feet tall - celebrated the nation's 1,260 operating railroad companies. But trains were about to go off the track. With automobiles encroaching on their preserve, the number of companies would decline nearly 36 percent by 1929, making their trademark "lonesome whistle" sound even more forlorn and desolate.