In 1909, “jaywalker” was an obscure Midwestern colloquial term that referred to a country hick in the city who got in the way of other pedestrians. But with the rise of the automobile, people connected with the auto industry used “jaywalker” to mean a pedestrian who crosses the street against regulations.
“Most people living in cities didn’t think fast cars belonged in streets,” Norton said. “So when cars hit pedestrians, it was always the driver’s fault. Angry city residents wrote letters to their newspapers denouncing ‘joy riders’ and ‘speed demons.’ But some people wanted to give cars a rightful claim to street space. The word ‘jaywalker’ was one way to do this. By casting doubt on pedestrians’ place in the street, it strengthened cars’ claim to street space. Making streets places for cars took not just regulations and devices such as traffic lights — language was also part of the struggle.”
Related to the discussion here.