smoothness=excellent		(thin_rollers) roller blade, skate board and all below
smoothness=good			(thin_wheels) racing bike and all below
smoothness=intermediate		(wheels) city bike, sport cars, wheel chair, Scooter and all below
smoothness=bad			(robust_wheels) trekking bike, normal cars, Rickshaw and all below
smoothness=very_bad		(high_clearance) Car with high clearance, light-duty off road vehicles
smoothness=horrible		(off_road_wheels) heavy-duty off road vehicles and all below
smoothness=very_horrible	(specialized_off_road_wheels) tractor, ATV, tanks, trial, Mountain bike and all kind of off-highway vehicles (see also mtb_scale=*)
smoothness=impassable		 No wheeled vehicle (see also sac_scale=*) 

Ich finde smoothness überhaupt nicht “schwachsinnig”. Es besagt doch ganz deutlich, ob ich dem Pfad mit einem Rennrad, oder Trekkingrad, oder doch lieber mit einem MTB begegnen sollte.
In Verbindung mit Highway=path ist dann sowieso klar, daß nur einspurige Fahrzeuge gemeint sind.