This week's entry is an educated guess as to the signifigance of something I spotted at the Studios. Unfortuately there isn't always an obvious or easy answer as to why something is in Disney's Hollywood Studios but based on the research I conducted, I'm fairly certain this is correct.
In the Gangster scene of the Great Movie Ride, before you exit the area and move onto the Western scene, you pass through a tunnel with a sign above it advertising to "Ride on the open air elevated".

The slogan of "Ride on the open air elevated" seems to refer to the New York City elevated railways that were prevelant from the 1870s through the 1930s in Manhattan. Notably the Sixth Avenue line, also known as the Sixth Avenue Elevated or Sixth Avenue El, was a famous elevated rail service. By the 1920s, ridership on elevated lines was dwindling, in favor of the subway, and an advertising campaign was started to encourage people to choose the elevated rail instead.
The first such station to offer this advertisement was the 38th Street station on the Sixth Avenue Elevated line on April 25, 1923 with the slogan "Ride on the open air elevated"
'
The advertising campaign didn't catch on and by 1938, the Sixth Avenue line shut down with other elevated train lines in New York closing in the following decades.