Origin of “Hang a Roscoe”

A caller from Los Angeles, California, wonders why we say “hang a Roscoe” for “turn right” when giving directions. This phrase, as well as “hang a Louie,” meaning “turn left,” go back at least as far as the 1960’s. These expressions are much like the military practice of using proper names for directional phrases in order to maintain clarity. Some people substitute the word bang for hang, as in “bang a Uey” (or U-ee) for “make a U-turn.” This is part of a complete episode.