Re:Braess' paradox: adding a new road to a city can slow dow...
by derefr on Friday October 16, 2015 @02:05AM
(#10397708)
To put the original paradox another way, though: if you run a road out of town far enough, somebody will build an airport at the end. The airport is indeed an "external source of new traffic", but it was built because the traffic system had enough unused capacity to absorb the projected load.
Re:Braess' paradox: adding a new road to a city can slow dow...
by sandworm101 on Friday October 16, 2015 @02:32AM
(#10397781)
I;m not convinced that the people building stadiums and airports go around looking for cities with extra traffic capacity. They are responding to forces well outside local traffic issues. The fact that they will generate increased traffic is a factor during planning and construction, but it is certainly not in any way a driving force behind the decision to build.
You cannot solve the problem of an external source of new traffic, be it a new stadium at the edge of town or new machine added to the edge of a network, by not building in any new capacity. Well, you could if you simply chose not to serve that new node. Not running any new roads to a new airport is a great way to get that airport to close, just as not serving that new customer on your network is a great way to make that customer go elsewhere.
The other flipside to the pardox is that it really is applicable to any network. Sometimes the best way to improve the efficiency of mass transit is to cull bus/train routes. But try selling that in a modern city.