Routes aren't infallible though, diversions occur because of predicable (planned maintenance) and unpredictable (crashes or weather incidents), and diversion routes may vary significantly.

Not an insurmountable problem - may even just be able to park the vehicle where a diversion route is unknown and wait for it to clear, but still an issue to deal with.

As the article explains, it's not about the predictability of the route, but of obstacles and changes along on the route.