Train Wave

The main decorative motif at Pennsylvania Station in Lancaster is a stylized wave that runs around the entire waiting room. Although Pennsylvania Station in Philadelphia is sparsely decorated, the same motif is visible inside the marble door frames. Here is a sketch of Philadelphia's train wave (1930):
... and Lancaster's train wave (1929).
I do not know enough about the Pennsylvania Railroad company to identify the wave as a corporate logo. But I do find it very evocative of the notion of movement through space, the blowing of steam and the rolling wheels articulated through the static language of classical architecture. Lancaster's station replicates the wave throughout the station, on the wooden seas and on the exterior facade:

Location: 40°03'25.70"N, 76°18'27.60"W
53 McGovern Avenue, Lancaster, PA 17602