I'm not sure what it's source is, but this page has prices for a variety of items, including travel and fuel:
http://www.paper-dragon.com/1939/priceguide.html (links at the bottom will take you to other useful info on the era).
As a point of interest,
according to Wolfram|Alpha, $1.00 in 1936 was roughly equivalent to $17.36 in 2015.