Until the early 1960s, automobiles that were moved by rail were carried in boxcars. These were 50 feet long with double-wide doors. Inside were room for four full-sized sedans on a two-tier rack - two raised up off the floor on a steel rack and two others tucked in underneath them. This protected the cars during transport but wasn’t very efficient has the weight of four vehicles was far less than the maximum weight a boxcar that size could carry.
The engineers at GM and the Southern Pacific Railroad came up with a clever solution. Instead of loading the cars horizontally, the Vegas will be placed vertically on a specially designed auto-rack – the Vert-A-Pac. Within the same volume of an 89-foot car, the Vert-A-Pac could hold as many as 30 automobiles instead of 18.
The Vega was hugely popular when it was introduced in 1970 however it quickly earned a reputation for unreliability, rust, safety issues and lousy engine durability. When the Vega was discontinued, the Vert-A-Pac cars had to be retired as they were too specialized to be used with anything else. The Vert-A-Pac racks were scrapped, and the underlying flatcars went on to other uses.