..when individual drivers seek the quickest route, they sometimes end up slowing things down for everybody.

GPS must add to this problem, especially on models that don’t dynamically adjust for traffic. Even with models that do, the Nash equilibrium may be sub-optimal.

I have not come across Braess’s Paradox before. It worries me. Most government intervention is built on the idea of ‘market failure’. A BP situation looks like the ultimate market failure, and could thus be an open door for additional regulation. Some of this would be good, if paternalist (a la Nudge). I worry that some may be bad, in freedom terms (i.e. planners get to override GPS updates).

The saving grace is that regulation to enforce the optimal outcome may be more costly that the gap between the optimal outcome and the Nash equilibrium.