Hypnosis, ESP, and psychology were all popular topics of interest at the time of this short and featured in many film plotlines.
Passenger air travel was steadily gaining in popularity at the time of this short, though most Americans still used the railroad for their trips. Superliner trains, like the one Roadrunner is shown racing, crossed the deserts as they ferried passengers across the country.
Although the colorful desert appears to be in the canyonlands around the Utah-Arizona border, Roadrunner zips past a Joshua Tree early on. This plant, a relative to the lily, is native to the Mojave Desert in California.
Hand grenades would have been a familiar sight to post-war film audiences.