Rue Sarrette (Paris 14ᵗʰ): Misinterpretation by Apple Maps Routing Despite Correct OSM Representation

I would like to document a recurring routing behavior observed in Apple Maps involving Rue Sarrette (Paris 14ᵗʰ arrondissement), which appears to conflict with both ground truth and the functional road hierarchy represented in OpenStreetMap (OSM). This note is not intended as a critique of OpenStreetMap data quality. On the contrary, it illustrates how accurately mapped local streets in OSM can still be misused by downstream routing engines, leading to results that diverge from real-world urban logic.

On the ground, Rue Sarrette is a clearly identifiable local residential street in the Petit-Montrouge area. It has a limited carriageway width, is primarily bordered by housing, and has no arterial or collector function. The street is designed for local access and neighborhood circulation, with moderate speeds and traffic levels consistent with a residential environment. From an OpenStreetMap perspective, Rue Sarrette is correctly mapped and tagged as a low-hierarchy residential road, with no attributes suggesting it should serve as a transit corridor. In practical terms, it is not designed, dimensioned, or intended to absorb through-traffic.

Despite this, Apple Maps frequently routes traffic along Rue Sarrette as part of longer itineraries through the area. This behavior is most often observed when Avenue du Général-Leclerc, a nearby arterial road, is algorithmically avoided. Rue Sarrette is then effectively used as a substitute transit route, even when the destination is not located on Rue Sarrette, when the detour provides no clear time or distance advantage, and when higher-capacity roads are available in close proximity.

This routing pattern is consistent, reproducible, and independent of temporary disruptions such as roadworks or incidents. It strongly suggests a routing-model issue in Apple Maps, where arterial roads are over-penalized and local residential 