Add road stop flag to not show one-way road overlays

src/newgrf_roadstop.h

@@ -65,6 +65,7 @@ DECLARE_ENUM_AS_BIT_SET(RoadStopDrawMode)
 
 enum RoadStopSpecFlags {
 	RSF_CB141_RANDOM_BITS,    ///< Callback 141 needs random bits.
+	RSF_NO_ONE_WAY_OVERLAY,   ///< Do not show one-way road overlays.
 };
 
 enum RoadStopSpecIntlFlags {

src/station_cmd.cpp

@@ -3546,7 +3546,7 @@ draw_default_foundation:
 			}
 
 			DisallowedRoadDirections drd = GetDriveThroughStopDisallowedRoadDirections(ti->tile);
-			if (drd != DRD_NONE) {
+			if (drd != DRD_NONE && (stopspec == nullptr || !HasBit(stopspec->flags, RSF_NO_ONE_WAY_OVERLAY))) {
 				DrawGroundSpriteAt(SPR_ONEWAY_BASE + drd - 1 + ((axis == AXIS_X) ? 0 : 3), PAL_NONE, 8, 8, 0);
 			}
 		} else {