Blue flag protection, 2010.

This well-known signal, shown here in Fort Worth, Texas, conveys to all train and engine employees that work is being performed on the track and that it is unsafe to pass.

Bi-level Superliner cars like the one seen in the distance were first constructed for Amtrak by Pullman Standard in the late 1970s. The original order included 102 coaches, 48 coach-baggage cars, 25 café/lounge cars, 70 sleepers and 39 diners.

Amtrak accepted the first Superliner in October 1978, and it was used for the training of on-board service and maintenance crews. Built to be pulled at speeds up to 100 mph, the cars measure 85 feet long (to the ends of the couplers), approximately 10 feet wide and 16 feet high. Amtrak placed an order with Bombardier in 1991 for an additional 140 (later increased to 195) "Superliner II" cars.

This image is one of a set entitled "A Day in the Life of Amtrak" completed for the Amtrak 40th Anniversary celebration.

Photographer: William Shaffer for Amtrak. From the Amtrak Corporate Collection.