Index: src/settings.cpp
===================================================================
--- src/settings.cpp	(revision 12913)
+++ src/settings.cpp	(working copy)
@@ -1437,6 +1437,7 @@
 	SDT_CONDVAR(Patches, pathfinder_for_ships,    SLE_UINT8, 87, SL_MAX_VERSION, 0, MS, 0, 0, 2, 1, STR_CONFIG_PATCHES_PATHFINDER_FOR_SHIPS,   NULL),
 
 	SDT_BOOL(Patches, train_income_warn,             S, 0,  true,                    STR_CONFIG_PATCHES_WARN_INCOME_LESS,     NULL),
+	SDT_BOOL(Patches, vehicle_late_warn,             S, 0,  true,                    STR_CONFIG_PATCHES_WARN_RUNNING_LATE,    NULL),
 	 SDT_VAR(Patches, order_review_system,SLE_UINT8, S,MS,     2,     0,       2, 0, STR_CONFIG_PATCHES_ORDER_REVIEW,         NULL),
 	SDT_BOOL(Patches, never_expire_vehicles,         0,NN, false,                    STR_CONFIG_PATCHES_NEVER_EXPIRE_VEHICLES,NULL),
 	SDT_BOOL(Patches, lost_train_warn,               S, 0,  true,                    STR_CONFIG_PATCHES_WARN_LOST_TRAIN,      NULL),
Index: src/lang/english.txt
===================================================================
--- src/lang/english.txt	(revision 12913)
+++ src/lang/english.txt	(working copy)
@@ -985,6 +985,7 @@
 
 STR_TRAIN_IS_LOST                                               :{WHITE}Train {COMMA} is lost.
 STR_TRAIN_IS_UNPROFITABLE                                       :{WHITE}Train {COMMA}'s profit last year was {CURRENCY}
+STR_VEHICLE_IS_VERY_LATE                                        :{WHITE}Vehicle {COMMA} is running running over a month late
 STR_EURO_INTRODUCE                                              :{BLACK}{BIGFONT}European Monetary Union!{}{}The Euro is introduced as the sole currency for everyday transactions in your country!
 
 # Start of order review system.
@@ -1063,6 +1064,7 @@
 STR_CONFIG_PATCHES_ORDER_REVIEW_EXDEPOT                         :yes, but exclude stopped vehicles
 STR_CONFIG_PATCHES_ORDER_REVIEW_ON                              :of all vehicles
 STR_CONFIG_PATCHES_WARN_INCOME_LESS                             :{LTBLUE}Warn if a train's income is negative: {ORANGE}{STRING1}
+STR_CONFIG_PATCHES_WARN_RUNNING_LATE                            :{LTBLUE}Warn if a vehicle runs more than a month late: {ORANGE}{STRING1}
 STR_CONFIG_PATCHES_NEVER_EXPIRE_VEHICLES                        :{LTBLUE}Vehicles never expire: {ORANGE}{STRING1}
 STR_CONFIG_PATCHES_AUTORENEW_VEHICLE                            :{LTBLUE}Autorenew vehicle when it gets old
 STR_CONFIG_PATCHES_AUTORENEW_MONTHS                             :{LTBLUE}Autorenew when vehicle is {ORANGE}{STRING1}{LTBLUE} months before/after max age
Index: src/settings_gui.cpp
===================================================================
--- src/settings_gui.cpp	(revision 12913)
+++ src/settings_gui.cpp	(working copy)
@@ -798,6 +798,7 @@
 	"pathfinder_for_roadvehs",
 	"pathfinder_for_ships",
 	"train_income_warn",
+	"vehicle_late_warn",
 	"order_review_system",
 	"never_expire_vehicles",
 	"lost_train_warn",
Index: src/timetable_cmd.cpp
===================================================================
--- src/timetable_cmd.cpp	(revision 12913)
+++ src/timetable_cmd.cpp	(working copy)
@@ -11,6 +11,8 @@
 #include "vehicle_func.h"
 #include "vehicle_base.h"
 #include "settings_type.h"
+#include "strings_func.h"
+#include "news_func.h"
 
 #include "table/strings.h"
 
@@ -100,6 +102,7 @@
 
 	if (flags & DC_EXEC) {
 		v->lateness_counter = 0;
+		v->lateness_reported = 0;
 	}
 
 	return CommandCost();
@@ -191,6 +194,26 @@
 
 	v->lateness_counter -= (timetabled - time_taken);
 
+	/* If the vehicle is now running badly late, issue a warning message.
+	 * Use some basic hysteresis to avoid doing this over and over. */
+	if (_patches.vehicle_late_warn) {
+		if (v->lateness_reported) {
+			if (v->lateness_counter < (DAY_TICKS * 20)) {
+				v->lateness_reported = 0;
+			}
+		} else {
+			if (v->lateness_counter > (DAY_TICKS * 30)) {
+				SetDParam(0, v->unitnumber);
+				AddNewsItem(
+					STR_VEHICLE_IS_VERY_LATE,
+					NM_SMALL, NF_VIEWPORT | NF_VEHICLE, NT_ADVICE, DNC_NONE,
+					v->index,
+					0);
+				v->lateness_reported = 1;
+			}
+		}
+	}
+
 	for (v = GetFirstVehicleFromSharedList(v); v != NULL; v = v->next_shared) {
 		InvalidateWindow(WC_VEHICLE_TIMETABLE, v->index);
 	}
Index: src/settings_type.h
===================================================================
--- src/settings_type.h	(revision 12913)
+++ src/settings_type.h	(working copy)
@@ -76,6 +76,7 @@
 	bool lost_train_warn;               ///< if a train can't find its destination, show a warning
 	uint8 order_review_system;
 	bool train_income_warn;             ///< if train is generating little income, show a warning
+	bool vehicle_late_warn;             ///< if a vehicle is running more than a month late, show a warning
 	bool status_long_date;              ///< always show long date in status bar
 	bool signal_side;                   ///< show signals on right side
 	bool show_finances;                 ///< show finances at end of year
Index: src/vehicle.cpp
===================================================================
--- src/vehicle.cpp	(revision 12913)
+++ src/vehicle.cpp	(working copy)
@@ -2276,6 +2276,7 @@
 
 	SLE_CONDVAR(Vehicle, current_order_time,   SLE_UINT32,                67, SL_MAX_VERSION),
 	SLE_CONDVAR(Vehicle, lateness_counter,     SLE_INT32,                 67, SL_MAX_VERSION),
+	SLE_CONDVAR(Vehicle, lateness_reported,    SLE_UINT8,                 94, SL_MAX_VERSION),
 
 	/* reserve extra space in savegame here. (currently 10 bytes) */
 	SLE_CONDNULL(10,                                                       2, SL_MAX_VERSION),
Index: src/vehicle_base.h
===================================================================
--- src/vehicle_base.h	(revision 12913)
+++ src/vehicle_base.h	(working copy)
@@ -220,6 +220,7 @@
 	/* Used for timetabling. */
 	uint32 current_order_time;     ///< How many ticks have passed since this order started.
 	int32 lateness_counter;        ///< How many ticks late (or early if negative) this vehicle is.
+	byte lateness_reported;        ///< Flag that severe vehicle lateness has already been reported.
 
 	/* Boundaries for the current position in the world and a next hash link.
 	 * NOSAVE: All of those can be updated with VehiclePositionChanged() */