This week, a viral video of a robo-traffic-cop in Shanghai has the team contemplating the science of traffic. How do traffic jams with no discernible cause actually form? Does the weather experience traffic jams? And why do our cords also seem to get tangled in their own little cord-traffic-jams no matter how hard we try to keep them separate?

Christine Yohannes from Addis Ababa, Ethiopia and Tristan Ahtone in Helsinki, Finland, join Marnie Chesterton to discuss all this, plus many more Unexpected Elements.

Presenter: Marnie Chesterton, with Christine Yohannes and Tristan Ahtone
Producers: Margaret Sessa-Hawkins, with Alice Lipscombe-Southwell and Lucy Davies