The French highway A 154 / N 154, which runs from Incarville south of Rouen 49.23889, 1.186318 via Dreux and Chartres to Exit 12 on the A10 motorway 48.206106, 1.845638, shows as a highway on Openstreet map, but its route does not show on maps using the Leaflet routing machine. The routing machine shows a weird and wonderful alternative using other devious routes all over the countryside