I can't say this actually happened for me. For straightforward routes with no congestion I never saw random alternate routes being proposed. That makes sense, given that it'd probably tip people off. If this is happening, they must only be doing in cases where there's congestion and the difference is marginal, eg. it's rush hour and the "optimal" route takes 30 minutes but the alternate takes 33 minutes. Moreover you don't really need any deliberate effort to see this effect. If nobody is traveling on a side road, the algorithm will probably revert to historical patterns, which might turn out to be overly optimistic in congestion scenarios (eg. there's nearby road repairs and other people are already using it as an alternate), thereby giving you the impression that you got screwed over by the app.
For instance, a few years ago, a segment of I-495 in Delaware needed to be unexpectedly shut down for emergency repairs. Drivers were rerouted. But because of the increase in traffic on the less-hardy detour route, that route needed repairs and repaving soon afterward, much more quickly than it would have ordinarily required.
So yes, drivers can be better dispersed to ease congestion, but we also need to consider the secondary effects to the roadways themselves.
https://patents.google.com/patent/US20170184409A1
(I'm not saying I'm the first or only person to think of it, but I did patent it, as well as the extra claim of compensating those people sent on the slower route).
gruez•1h ago
Why would they specifically need to route people away from congested segments? Presumably if a segment gets congested enough, it'd be considered slower and therefore won't get picked in the first place?
glalonde•1h ago
Every actor acting rationally in their own interest can get to a worse equilibrium than if they were coordinated(in this case, to completely ignore the new edge). There are many other examples of this in game theory, you should look it up.