You are in the CarrTracks website Picture Gallery.
Not far away was this Sperry Rail detector. SRS137 was built from a Soo Line doodlebug. I was more acquainted with one of Dr. Elmer Sperry's other ventures, that of gyros. One of my responsibilities on the submarine was maintaining three Sperry Univac computers. Gyros were used in the inertial navigation systems where I was Navigation Center Supervisor.
No it is not what you are thinking. Zooming in reveals what is actually going on. An attendant was washing off some of the road grime. This is the full resolution of the TIF files that are on the disks. Disk 38