"greedy algorithms do not appear capable of producing optimal lane changes"

It's fairly likely every driver has at some point cared about maximizing their speed on the road (to some limit haha), and that implies they care about minimizing delays caused by traffic. In this universe at least, this means changing lanes. The recurring problem is selecting the best lane at a given time.

A greedy algorithm is one where the locally optimal choice is always made, without thinking about the big picture. In theory, I think that a greedy algorithm would work: the instant the current lane becomes worse than another, the obvious remedy is to use that other lane. At the end of the day, one would be the furthest ahead because only the best lanes had been used. In real life, though, switching at any given moment may be impossible due to other traffic, causing a loss of several car lengths while one waits for an "opening".