August 26, 2008
| Numa Numa Rihanna >>
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!
Subscribe
Comments
The most interesting thing about these experiments is that there is a critical number of cars. Below the critical number, the flow continues smoothly, but once you cross the critical point (within a window of about 1-2 cars) you get a jam.