I'm pretty confident Waze routes people not by posted speed limits, but by average driving habits and traffic speeds.
I do think Waze users are self-selecting. People that are willing to take "short cuts" choose Waze. I often ignore Waze's suggestions and have had people in the car with me comment on the extra turns and backroads.
There's a certain type of driver who prefers to mostly "tune out" and take the most direct route versus someone who wants to get there with the quickest ETA even if that means a more complex route.
I'd be amazed if this is true. Especially as Waze has a GPS based speedometer built in that goes red if you go over the speed limit.
I image it looks at a combination of speed limit, current traffic and then if the historical data is faster than the speed limit it discards the historical data.
Just anecdotally I feel like I have to drive fairly aggressively to meet the estimates. I'm quick to disregard Waze because it will often throw me into an awkward intersection where I know taking a route with fewer turns would get me there faster. Waze also doesn't have speed data for many stretches of road. As it got added (and since) I haven't noticed any changes in routing or ETAs. I'd be very curious about an actual answer, but that's why I suspect it doesn't use it.
I do think Waze users are self-selecting. People that are willing to take "short cuts" choose Waze. I often ignore Waze's suggestions and have had people in the car with me comment on the extra turns and backroads.
There's a certain type of driver who prefers to mostly "tune out" and take the most direct route versus someone who wants to get there with the quickest ETA even if that means a more complex route.