The roadmap was a complimentary product and, more importantly to the oil company which provided it, an advertisement for gasoline. The images oil companies used to market their gasoline were often common tourist destinations, less geographically specific picturesque natural scenes and symbols of local culture. Some maps featured pictures of travelers rather than their destinations. With surprising frequency, women were shown behind the wheel (Yorke, 63-66). In his book The Automobile Age, James Flink argues that not just oil companies, but auto marketers and auto makers made a concerted effort to appeal to women. He asserts that this had been the case since 1912, with the introduction of the self-starter, also called the "ladies aid" (162). This device made it possible to start the car without the inconvenience and struggle of hand-cranking. He sees "most comfort and convenience options added to cars since then -- including vanity mirrors, plush upholstery, heaters, air conditioning, and automatic transmissions", as similar attempts to appeal to women (Flink, 163).
Many of these road maps are visually striking; they are also interesting for what they reveal about idealized visions of travel in the 1930s.