Earlier quoted context omitted.
10mph is blazingly, exceptionally fast for an interstate in a major city during commute hours. Building bigger highways sparks further-flung suburbs and the new traffic brings everyone else's commute times back to equilibrium.
Indeed, you can see this in the Dallas area. The major roads have run out of room to expand and according to the old timers traffic is no better than it was in 1990. All the road expansion did was let people move to ever more distant suburbs.
Yes, this is called 'induced demand.'[1] And I think that Waze may be planning its own obsolescense: once it has optimized all the streets and roads in a city, they will all be equally slow.
[1] https://en.wikipedia.org/wiki/Induced_demand#Elasticity_of_t...