Re: game theory etc.

[Jon Pike <jhpike@xxxxxxx>]

> In V9 #627, Joe Elliott asks me about the Nature article I cite. The article is "Coherent moving staes in highway traffic" by Dirk Helbing of Stuttgart, Germany, and Bernardo A. Huberman of Palo Alto, California (Nature; 396: 738-740 [24/31 December 1998]). The article can be found at www.nature.com. 
> The investigators use a multiagent simulation technique which has made possible the study of realistic highway traffic patterns and has allowed theories based on driver behavior to be tested. The model assumes competitive interaction between the players and different desired speeds for cars and lorries (large trucks). The model finds that as vehicles are added to a highway, traffic will gradually tend to move in a coherent state as a solid block, at which point its capacity is maximized. Adding more cars will cause a rapid breakdown of the coherent state and stop-and-go traffic. (This must be why they have highway on-ramp meter signals in LA).
Hmmm...  some 10 odd years ago I had a little too much spare time 
(probably stuck in traffic) and I came up with the comparative concept 
of traffic as a fluid.

This then extended out to traffic as a multi state substance. If you 
increase the density,  you get to a saturation point where it quickly 
condenses into a more organized state,  with the cars moving mostly 
together with roughly equal, shorter distances.  (traffic is a liquid)

Eventually you get to traffic as a solid, or supercooled liquid,  i.e. 
traffic jam.   Now, if you reduce the density/pressure,  traffic is a 
gas with all particles moving freely with lots of space between them.   
Ever notice the state change when you get past the accident or 
whatever,  and the overheated fluid quickly "boils" off into the gaseous 
state?

Like I said..  too much time on the hands,  or brain in this case.

I also noticed standing waves in traffic,  before whoever published a 
paper on it.. 
Uh,  Alfa's Rule!!  (Alfa content to keep Richard happy)  ;-)

So, moral to the story.. when in traffic,  go with the Flow! 
Jon
77 Spider
--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided