diff --git a/npf.c b/npf.c
--- a/npf.c
+++ b/npf.c
@@ -542,7 +542,7 @@ static void NPFFollowTrack(AyStar* aysta
 		/* Find out the exit direction first */
 		if (IsRoadStationTile(src_tile)) {
 			exitdir = GetRoadStationDir(src_tile);
-		} else { /* Train or road depot. Direction is stored the same for both, in map5 */
+		} else { /* Train or road depot */
 			exitdir = GetDepotDirection(src_tile, type);
 		}
 
diff --git a/openttd.h b/openttd.h
--- a/openttd.h
+++ b/openttd.h
@@ -110,11 +110,10 @@ enum InitializeGameModes {
 
 typedef enum TransportTypes {
 	/* These constants are for now linked to the representation of bridges
-	 * and tunnels, so they can be used by GetTileTrackStatus_TunnelBridge
-	 * to compare against the map5 array. In an ideal world, these
-	 * constants would be used everywhere when accessing tunnels and
-	 * bridges. For now, you should just not change the values for road
-	 * and rail.
+	 * and tunnels, so they can be used by GetTileTrackStatus_TunnelBridge.
+	 * In an ideal world, these constants would be used everywhere when
+	 * accessing tunnels and bridges. For now, you should just not change
+	 * the values for road and rail.
 	 */
 	TRANSPORT_RAIL = 0,
 	TRANSPORT_ROAD = 1,
diff --git a/rail_cmd.c b/rail_cmd.c
--- a/rail_cmd.c
+++ b/rail_cmd.c
@@ -38,16 +38,6 @@ const byte _track_sloped_sprites[14] = {
 
 void ShowTrainDepotWindow(TileIndex tile);
 
-/* Format of rail map5 byte.
- * 00 abcdef  => Normal rail
- * 01 abcdef  => Rail with signals
- * 10 ??????  => Unused
- * 11 ????dd  => Depot
- *
- * abcdef is a bitmask, which contains ones for all present tracks. Below the
- * value for each track is given.
- */
-
 /*         4
  *     ---------
  *    |\       /|
@@ -582,7 +572,7 @@ int32 CmdRemoveRailroadTrack(int x, int 
 /** Build a train depot
  * @param x,y position of the train depot
  * @param p1 rail type
- * @param p2 depot direction (0 through 3), where 0 is NE, 1 is SE, 2 is SW, 3 is NW
+ * @param p2 entrance direction (DiagDirection)
  *
  * @todo When checking for the tile slope,
  * distingush between "Flat land required" and "land sloped in wrong direction"
diff --git a/road_cmd.c b/road_cmd.c
--- a/road_cmd.c
+++ b/road_cmd.c
@@ -553,7 +553,7 @@ int32 CmdRemoveLongRoad(int x, int y, ui
 
 /** Build a road depot.
  * @param x,y tile coordinates where the depot will be built
- * @param p1 depot direction (0 through 3), where 0 is NW, 1 is NE, etc.
+ * @param p1 entrance direction (DiagDirection)
  * @param p2 unused
  *
  * @todo When checking for the tile slope,
diff --git a/station.h b/station.h
--- a/station.h
+++ b/station.h
@@ -242,8 +242,9 @@ static inline bool IsBuoyTile(TileIndex 
 	return IsTileType(tile, MP_STATION) && _m[tile].m5 == 0x52;
 }
 
-/* Get's the direction the station exit points towards. Ie, returns 0 for a
- * station with the exit NE. */
+/**
+ * Get's the direction the road stop entrance points towards.
+ */
 static inline DiagDirection GetRoadStationDir(TileIndex tile)
 {
 	assert(IsRoadStationTile(tile));
diff --git a/station_cmd.c b/station_cmd.c
--- a/station_cmd.c
+++ b/station_cmd.c
@@ -1293,7 +1293,7 @@ static void FindRoadStationSpot(bool tru
 
 /** Build a bus station
  * @param x,y coordinates to build bus station at
- * @param p1 busstop entrance direction (0 through 3), where 0 is NW, 1 is NE, etc.
+ * @param p1 entrance direction (DiagDirection)
  * @param p2 0 for Bus stops, 1 for truck stops
  */
 int32 CmdBuildRoadStop(int x, int y, uint32 flags, uint32 p1, uint32 p2)