For those of you killing time waiting to see if the Bay Bridge reopens on schedule, why not spend ten minutes watching this charming film, "The March of Progress," about the engineering marvel of the Key Route trains that once traveled back and forth on the lower deck of the bridge. The Key System served the East Bay from 1903 to 1960, and provided transbay service from the time of the bridge's construction in 1936 until 1958 when the lower deck was opened up to eastbound auto traffic.

Be forewarned, this old-timey documentary begins at, like, the dawn of time, and has to get through the Gold Rush and the '06 quake before it gets to talking about the trains. The bridge makes its first appearance at 7:10. And if you're wicked into this, you can watch part 2 here.