--- a/src/road_cmd.cpp Thu May 31 07:21:33 2007 +0000
+++ b/src/road_cmd.cpp Thu May 31 07:34:40 2007 +0000
@@ -427,12 +427,16 @@
case MP_STATION:
if (!IsDriveThroughStopTile(tile)) return CMD_ERROR;
if (HASBIT(GetRoadTypes(tile), rt)) return_cmd_error(STR_1007_ALREADY_BUILT);
+ /* Don't allow "upgrading" the roadstop when vehicles are already driving on it */
+ if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
break;
case MP_TUNNELBRIDGE:
if ((IsTunnel(tile) && GetTunnelTransportType(tile) != TRANSPORT_ROAD) ||
(IsBridge(tile) && GetBridgeTransportType(tile) != TRANSPORT_ROAD)) return CMD_ERROR;
if (HASBIT(GetRoadTypes(tile), rt)) return_cmd_error(STR_1007_ALREADY_BUILT);
+ /* Don't allow "upgrading" the bridge/tunnel when vehicles are already driving on it */
+ if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
break;
default: