Yep. Wave propagation is often the phenomena you observe when the flow inexplicably slows and when you get to the source there's nothing there. There are other reasons as well like short onramps, or onramps too close together.
Doesn't matter, there is -always- a pre-existing condition absolutely necessary that the roadway be at or near capacity.
Although not scientific, I suggest you get ahold of Koyaanisqatsi. Yes, I triple checked the spelling. Anyway, it has all the congested flow traffic you'd ever want to see set to a score by Philip Glbutt.
Oh gosh no. Don't waste your time. Even if you could collect reliable data this way (you can't) you don't have the skills to buttemble it into a coherent structure. Not your fault you've just run up against a problem some of us see all the time. Let me illustrate with a common transit example I pulled from my database from 4 years ago:
Let me take a moment to explain how personal observations of transit usage are wildly misleading:
Light Rail Myths and Realities 4960From "Numerical Simulations of a Three-Lane Tra c Model Using Cellular Automata" A. Karim Daoudia and Najem Moussa, CHINESE JOURNAL OF PHYSICS VOL. 41 , NO. 6 ... V. CONCLUSION In summary...
A very astute observation. Think about the statement; "I've never ridden on an empty train." Of course not, there was at least one pbuttenger; you. Now extend this, any individual observer is ten times more likely to see ten riders than one. All ten people riding see 10 riders. On the other train only one person sees the one person train occupancy.
This is why many transit advocates say the train is always full when they are riding. It is. They aren't lying, just wrong to trust anecdote.
Or these hypotheticals:
20 trains on a line. Trains 1 through 19 run empty and number 20 runs full. Interview all the pbuttengers. 100% agree that the trains run full all the time.
20 Trains on a line. Trains 1 through 10 run empty and trains 11 through 19 have one person and train 20 runs full (10 people). The average bus has 2 people yet 50% will still tell you they run full all the time.
BTW the same effect works for road congestion. ----
Hey did you hear about the genetically engineered chicken? Turns out people like legs and thighs so they got rid of all the parts that perform well in tests (like wings) and bred a super strain with 4 legs instead. How do they taste? No one knows, nobody can catch one. Get it? Our roads would be so much more pleasant and efficient if only we could get rid of the least performing elements.
