August 26, 2008
Shockwave Traffic Jams
Here’s the setup:
- You’re one of 20 or so cars driving around in a perfect circle.
- No seriously, it’s a perfect circle.
- So your only job is to follow the car in front of you.
- And keep your speed at around 20 miles per hour.
The result? You guessed it: traffic jams!
Check out the video evidence.
And apparently this experiment corresponds to real-world observation in at least one important way: In both cases, the “shockwave” of slow-down propagates back through cars at around 12 miles per hour. It’s pretty mesmerizing to watch.
Thanks, Mathematical Society of Traffic Flow!