Stop signs were always the red octagons we know today -- so how was the color chosen, and why has it stuck? Learn about the history and psychology of red traffic signals in this episode of BrainStuff.Learn more about advertising on the HowStuffWorks podcasts at www.howstuffworks.com/advertisers.htmAnd to learn about your ad choices when listening to podcasts, visit https://www.howstuffworks.com/privacy.htm#ad-choices
