Waze routing includes a mechanism to prevent routing off a highway/freeway only to be routed right back on the same highway/freeway. The assumption is that drivers will prefer to remain on the highway/freeway even if waze calculates that taking a series of ramps or other collector/distributor roads is slightly faster or shorter.
Waze routing will not present routes over a detour off a highway/freeway and back on that same highway/freeway when each of the following conditions are met: 1) the last segment on the highway/freeway before the detour has the same street name and same city name as the next highway/freeway segment after the detour, 2) the detour is more than one segment long, 3) the detour is over segments of a different road type than the highway/freeway, and 4) the detour is under the threshold length as defined below.
The threshold length if the highway/freeway is a freeway or a major highway is 5 kilometers. The threshold length if the highway is a minor highway is 500 meters.