Among many commuters, Waze (acquired by Google) has become a staple - some might say, a drug. Waze is an app that finds you the "best" (i.e. shortest) route to your destination. It is famous for routing people through strange, local roads, and intuitively dubious routes (e.g. it once told me to drive through an airport). Because it takes crowd-sourced congestion data as one of its inputs, there are reports that some residents of previously quiet neighborhoods are sending fake signals into the system to discourage Waze from sending traffic onto their streets.
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If you are a fan of Waze, let me pose you a few questions to think about.
Let's say you are trying to get from point A to point B.
Let's say there are 50 different possible routes to get from A to B. Some of these are marginally different (e.g. take a left turn one block later) while others are substantively different (e.g. avoid a stretch of highway).
At any moment in time (for example, at the time you enter your destination), one of those 50 routes is the shortest route between A (where you are) and B (where you are going).
Also, there are a bunch of other drivers also trying to get from A to B.
If Waze sends all the drivers to this shortest route, then this route will no longer be the shortest route.
So some cars will be sent down a route that is not currently the shortest route. Do these drivers know they are not on the shortest route? (Do you?)
Do Waze users know how the algorithm decides who to send down which route?
Should the software vendor disclose how they make decisions like this?
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Of course, these GPS route planners have transformed our driving experiences in a majorly positive way. Gone are the days where I am juggling and folding a paper map while trying to steer the car and paying attention to the traffic around me.
When you compare Waze to say a standard GPS route planner, what is the real difference?
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P.S.
(a) If we allow the road system to run for a long term, at "equilibrium," one should expect all 50 routes to have the same travel time (but different amounts of traffic). If there is an identifiable shortest route, then some drivers will shift there, making some other route better.
(b) Almost all press coverage of the "bias" of algorithms are related to identity politics. However, the truly difficult issues related to bias have nothing to do with race, income, gender, etc. Here is an example of a fairness issue that should get much more attention.
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