diff --git a/display/viewport.cc b/display/viewport.cc
index 1bb785ed1..2020db796 100644
--- a/display/viewport.cc
+++ b/display/viewport.cc
@@ -308,6 +308,7 @@ viewport_t::viewport_t( karte_t *world, const koord ij_off , sint16 x_off , sint
 	assert(world);
 
 	follow_convoi = convoihandle_t();
+	is_auto_ugm_follow_convoi = false;
 
 	this->ij_off = ij_off;
 	this->x_off = x_off;
diff --git a/display/viewport.h b/display/viewport.h
index d5a1c6990..2f9e45b2c 100644
--- a/display/viewport.h
+++ b/display/viewport.h
@@ -99,6 +99,12 @@ private:
 	 */
 	convoihandle_t follow_convoi;
 
+	/*
+	 * The current convoi to follow.
+	 * @author shingoushori
+	 */
+	bool is_auto_ugm_follow_convoi;
+
 	/**
 	 * Converts map_coord to map2d_coord actually used for main view.
 	 */
@@ -253,6 +259,9 @@ public:
 	 */
 	convoihandle_t get_follow_convoi() const { return follow_convoi; }
 
+	void set_auto_ugm_follow_convoi(bool janein) { is_auto_ugm_follow_convoi = janein; }
+	bool get_auto_ugm_follow_convoi() { return is_auto_ugm_follow_convoi; }
+
 	/**
 	 * @}
 	 */
diff --git a/gui/convoi_info_t.cc b/gui/convoi_info_t.cc
index f17dee74a..921e7bda6 100644
--- a/gui/convoi_info_t.cc
+++ b/gui/convoi_info_t.cc
@@ -391,9 +391,13 @@ bool convoi_info_t::action_triggered( gui_action_creator_t *comp,value_t /* */)
 		if(welt->get_viewport()->get_follow_convoi()==cnv) {
 			// stop following
 			welt->get_viewport()->set_follow_convoi( convoihandle_t() );
+			welt->get_viewport()->set_auto_ugm_follow_convoi(false);
 		}
 		else {
 			welt->get_viewport()->set_follow_convoi(cnv);
+			if(event_get_last_control_shift() == 2) {
+				welt->get_viewport()->set_auto_ugm_follow_convoi(true);
+			}
 		}
 		return true;
 	}
diff --git a/simworld.cc b/simworld.cc
index c2f33ea52..38b0e6ebf 100644
--- a/simworld.cc
+++ b/simworld.cc
@@ -3550,6 +3550,19 @@ void karte_t::sync_step(uint32 delta_t, bool do_sync_step, bool display )
 				new_xoff -= tile_raster_scale_x(-v.get_xoff(), rw);
 				new_yoff -= tile_raster_scale_y(-v.get_yoff(), rw) + tile_raster_scale_y(new_pos.z * TILE_HEIGHT_STEP, rw);
 				viewport->change_world_position( new_pos.get_2d(), -new_xoff, -new_yoff );
+
+				// auto underground
+				if(viewport->get_auto_ugm_follow_convoi()){
+					grund_t *gr = lookup_kartenboden(new_pos.get_2d());
+					if(new_pos.z < gr->get_hoehe()) {
+						grund_t::set_underground_mode(grund_t::ugm_level, new_pos.z);
+					}
+					else {
+						grund_t::set_underground_mode(grund_t::ugm_none, 0);
+					}
+					// recalc all images on map
+					update_underground();
+				}
 			}
 		}