[smashd]

One could argue that Waze is virtually "adding lanes to the road" by finding all these alternate routes. Yet you'll see a lot of articles that claim that adding lanes just encourages more people to drive, which is nice for those people but does not improve congestion issues overall. Will this relationship also hold true with Waze over the long term?

If it does, Waze isn't really adding any long-term benefit to a city's traffic problem. It's playing a (arguably) zero-sum game with convenience, adding it to some people's lives and removing it from others. Waze users gain the convenience of driving in scenarios where they normally wouldn't, but the extra drivers are an inconvenience to residents of affected streets and city planners.

Measuring this effect sounds difficult because of extra distribution of the traffic, although I suppose you could come up with a "Waze factor" to estimate total traffic based solely on numbers from major roads. I'm going to guess that this work will fall on city planners and traffic engineers, not Waze.