Reduce frequency of brake overheating breakdowns

Decay overheat state more quickly
Avoid double-triggering overheating
Make overheating speed-dependent

src/ground_vehicle.hpp

@@ -468,10 +468,12 @@ protected:
 			}
 		}
 
+		bool brake_overheated = false;
 		if (this->cur_speed > max_speed) {
 			if (use_realistic_braking && accel.braking >= 0) {
-				extern void TrainBrakesOverheatedBreakdown(Vehicle *v);
-				TrainBrakesOverheatedBreakdown(this);
+				extern void TrainBrakesOverheatedBreakdown(Vehicle *v, int speed, int max_speed);
+				TrainBrakesOverheatedBreakdown(this, this->cur_speed, max_speed);
+				brake_overheated = true;
 			}
 			tempmax = std::max(this->cur_speed - (this->cur_speed / 10) - 1, max_speed);
 		}
@@ -480,9 +482,9 @@ protected:
 			new_subspeed = Clamp(advisory_max_speed << 8, new_lb_subspeed, new_subspeed);
 
 			if ((new_subspeed >> 8) > tempmax) {
-				if (use_realistic_braking && accel.braking >= 0) {
-					extern void TrainBrakesOverheatedBreakdown(Vehicle *v);
-					TrainBrakesOverheatedBreakdown(this);
+				if (use_realistic_braking && accel.braking >= 0 && !brake_overheated) {
+					extern void TrainBrakesOverheatedBreakdown(Vehicle *v, int speed, int max_speed);
+					TrainBrakesOverheatedBreakdown(this, (new_subspeed >> 8), tempmax);
 				}
 				new_subspeed = tempmax << 8;
 			}

src/train_cmd.cpp

@@ -6607,7 +6607,7 @@ static bool TrainLocoHandler(Train *v, bool mode)
 		return mode ? true : HandleCrashedTrain(v); // 'this' can be deleted here
 	} else if (v->crash_anim_pos > 0) {
 		/* Reduce realistic braking brake overheating */
-		v->crash_anim_pos--;
+		v->crash_anim_pos -= (v->crash_anim_pos + 255) >> 8;
 	}
 
 	if (v->force_proceed != TFP_NONE) {
@@ -7565,8 +7565,9 @@ void TrainRoadVehicleCrashBreakdown(Vehicle *v)
 	t->reliability = 0;
 }
 
-void TrainBrakesOverheatedBreakdown(Vehicle *v)
+void TrainBrakesOverheatedBreakdown(Vehicle *v, int speed, int max_speed)
 {
+	if (v->type != VEH_TRAIN) return;
 	Train *t = Train::From(v)->First();
 	if (t->breakdown_ctr != 0 || (t->vehstatus & VS_CRASHED)) return;
 
@@ -7574,7 +7575,7 @@ void TrainBrakesOverheatedBreakdown(Vehicle *v)
 		ShowVehicleViewWindow(t);
 	}
 
-	t->crash_anim_pos = std::min<uint>(1500, t->crash_anim_pos + 200);
+	t->crash_anim_pos = std::min<uint>(1500, t->crash_anim_pos + Clamp(((speed - max_speed) * speed) / 2, 0, 500));
 	if (t->crash_anim_pos < 1500) return;
 
 	t->breakdown_ctr = 2;