4 ms·

Here's a brief demo [video] of how these jams can start for no apparent reason http://www.youtube.com/watch?v=Suugn-p5C1M http://www.youtube.com/watch?v=Suugn-p

• Splines 15y ago
  It must have taken careful coordination to get them into the starting position too. I'd be interested to see videos of solutions they've come up with. They could even try solutions that exist today (variable speed limits, hard shoulder openings, ramps with traffic lights when adding cars, etc.).