The B&O kept the 1893 crossing as a connection to the Shenendoah Valley Branch
it had leased and eventually purchased from the W&P. That line continues in
use today as CSX's Shenendoah Subdivision, seen here as the tracks curving
off the right edge of the photo. Prior to the 1931 bridge, the tracks curving
to the left provided the connection northwest to Cumberland, MD.
When a 1936 flood destroyed the road bridge over the century-old alignment, this
bridge was pressed into shared service as a temporary, single-lane automobile
bridge. World War II delayed construction of a dedicated automobile replacement
until in 1947 US 340 spanned the Potomac over Sandy Hook, as seen earlier.
More recently, a crossing for passengers was added to the bridge, even
though strictly prohibited by this B&O vintage sign. It seems unlikely any
B&O RR police will be around to enforce the rule.
Links to older pics: