Index: src/train_cmd.cpp
===================================================================
--- src/train_cmd.cpp	(revision 27760)
+++ src/train_cmd.cpp	(working copy)
@@ -3901,11 +3901,21 @@
 {
 	Money cost = 0;
 	const Train *v = this;
+	uint16 unc_len = 0;
 
 	do {
 		const Engine *e = v->GetEngine();
-		if (e->u.rail.running_cost_class == INVALID_PRICE) continue;
 
+		if (e->u.rail.running_cost_class == INVALID_PRICE) {
+			const Train *a = v;
+
+			do {
+				unc_len += a->gcache.cached_veh_length;
+				a = a->HasArticulatedPart() ? a->GetNextArticulatedPart() : NULL;
+			} while (a != NULL);
+			continue;
+		}
+
 		uint cost_factor = GetVehicleProperty(v, PROP_TRAIN_RUNNING_COST_FACTOR, e->u.rail.running_cost);
 		if (cost_factor == 0) continue;
 
@@ -3915,7 +3925,7 @@
 		cost += GetPrice(e->u.rail.running_cost_class, cost_factor, e->GetGRF());
 	} while ((v = v->GetNextVehicle()) != NULL);
 
-	return cost;
+	return cost += cost * unc_len / (VEHICLE_LENGTH * 2 * _settings_game.vehicle.max_train_length);
 }
 
 /**