# How do stoplights know when to change?

An episode of [Moment Of Um](https://invisiblenetwork.ai/podcast/1603857929), 4 Jun 2025, 6:09.

Audio: https://www.podtrac.com/pts/redirect.mp3/pdst.fm/e/claritaspod.com/measure/pscrb.fm/rss/p/mgln.ai/e/491/traffic.megaphone.fm/LEME5806537091.mp3?updated=1774643550

Waiting for a stoplight to turn green can be really annoying, especially when you’re running late. It would be awesome if you had a magic wand you could wave to get the light to change. But alas, such things don’t exist. But how do stoplights know when to switch colors? We asked Jerry Kotzenmacher with the Minnesota Department of Transportation to help us find the answer. Got a nagging question that just won’t yield? Send it to us at BrainsOn.org/contact, and we’ll put you in the express lane to answersville. See omnystudio.com/listener for privacy information.

Shows are listed from Apple Podcasts' charts and directory, and Podcast Index where it is used. Every show and episode belongs to its publisher and plays from the publisher's own feed; this site hosts none of them.