About this episode
When were Traffic Lights first invented? What were early Traffic Lights like? Where did the idea for Traffic Lights come from? Have you started your FREE TRIAL of Who Smarted?+ for AD FREE listening, an EXTRA episode every week & bonus content? Sign up right in the Apple app, or directly at WhoSmarted.com and find out why more than 1,000 families are LOVING their subscription! Get official Who Smarted? Merch: tee-shirts, mugs, hoodies and more, at Who Smarted?