--- a/src/tunnel_map.h	Wed Jun 13 11:17:30 2007 +0000
+++ b/src/tunnel_map.h	Wed Jun 13 11:45:14 2007 +0000
@@ -9,8 +9,14 @@
 #include "macros.h"
 #include "map.h"
 #include "rail.h"
+#include "road.h"
 
-
+/**
+ * Is this a tunnel (entrance)?
+ * @param t the tile that might be a tunnel
+ * @pre IsTileType(t, MP_TUNNELBRIDGE)
+ * @return true if and only if this tile is a tunnel (entrance)
+ */
 static inline bool IsTunnel(TileIndex t)
 {
 	assert(IsTileType(t, MP_TUNNELBRIDGE));
@@ -18,31 +24,60 @@
 }
 
 
+/**
+ * Is this a tunnel (entrance)?
+ * @param t the tile that might be a tunnel
+ * @return true if and only if this tile is a tunnel (entrance)
+ */
 static inline bool IsTunnelTile(TileIndex t)
 {
 	return IsTileType(t, MP_TUNNELBRIDGE) && IsTunnel(t);
 }
 
-
+/**
+ * Gets the direction facing out of the tunnel
+ * @param t the tile to get the tunnel facing direction of
+ * @pre IsTunnelTile(t)
+ * @return the direction the tunnel is facing
+ */
 static inline DiagDirection GetTunnelDirection(TileIndex t)
 {
 	assert(IsTunnelTile(t));
 	return (DiagDirection)GB(_m[t].m5, 0, 2);
 }
 
-
+/**
+ * Gets the transport type of the tunnel (road or rail)
+ * @param t the tunnel entrance tile to get the type of
+ * @pre IsTunnelTile(t)
+ * @return the transport type in the tunnel
+ */
 static inline TransportType GetTunnelTransportType(TileIndex t)
 {
 	assert(IsTunnelTile(t));
 	return (TransportType)GB(_m[t].m5, 2, 2);
 }
 
+/**
+ * Is this tunnel entrance in a snowy or desert area?
+ * @param t the tunnel entrance tile
+ * @pre IsTunnelTile(t)
+ * @return true if and only if the tunnel entrance is in a snowy/desert area
+ */
 static inline bool HasTunnelSnowOrDesert(TileIndex t)
 {
 	assert(IsTunnelTile(t));
 	return HASBIT(_m[t].m4, 7);
 }
 
+/**
+ * Places this tunnel entrance in a snowy or desert area,
+ * or takes it out of there.
+ * @param t the tunnel entrance tile
+ * @param snow_or_desert is the entrance in snow or desert (true), when
+ *                       not in snow and not in desert false
+ * @pre IsTunnelTile(t)
+ */
 static inline void SetTunnelSnowOrDesert(TileIndex t, bool snow_or_desert)
 {
 	assert(IsTunnelTile(t));
@@ -54,16 +89,30 @@
 bool IsTunnelInWay(TileIndex, uint z);
 
 
-static inline void MakeRoadTunnel(TileIndex t, Owner o, DiagDirection d)
+/**
+ * Makes a road tunnel entrance
+ * @param t the entrance of the tunnel
+ * @param o the owner of the entrance
+ * @param d the direction facing out of the tunnel
+ * @param r the road type used in the tunnel
+ */
+static inline void MakeRoadTunnel(TileIndex t, Owner o, DiagDirection d, RoadTypes r)
 {
 	SetTileType(t, MP_TUNNELBRIDGE);
 	SetTileOwner(t, o);
 	_m[t].m2 = 0;
-	_m[t].m3 = 0;
+	_m[t].m3 = r;
 	_m[t].m4 = 0;
 	_m[t].m5 = TRANSPORT_ROAD << 2 | d;
 }
 
+/**
+ * Makes a rail tunnel entrance
+ * @param t the entrance of the tunnel
+ * @param o the owner of the entrance
+ * @param d the direction facing out of the tunnel
+ * @param r the rail type used in the tunnel
+ */
 static inline void MakeRailTunnel(TileIndex t, Owner o, DiagDirection d, RailType r)
 {
 	SetTileType(t, MP_TUNNELBRIDGE);