Give monorail/maglev larger realistic braking deceleration limits

src/ground_vehicle.cpp

@@ -156,7 +156,8 @@ GroundVehicleAcceleration GroundVehicle<T, Type>::GetAcceleration()
 	 */
 	int64 resistance = 0;
 
-	bool maglev = v->GetAccelerationType() == 2;
+	int accleration_type = v->GetAccelerationType();
+	bool maglev = (accleration_type == 2);
 
 	const int area = v->GetAirDragArea();
 	if (!maglev) {
@@ -250,7 +251,7 @@ GroundVehicleAcceleration GroundVehicle<T, Type>::GetAcceleration()
 
 		/* Defensive driving: prevent ridiculously fast deceleration.
 		 * -130 corresponds to a braking distance of about 6.2 tiles from 160 km/h. */
-		braking_accel = std::max(braking_accel, -130);
+		braking_accel = std::max(braking_accel, -(GetTrainRealisticBrakingTargetDecelerationLimit(accleration_type) + 10));
 	} else {
 		braking_accel = ClampToI32(std::min<int64>(-braking_force - resistance, -10000) / mass);
 	}

src/train.h

@@ -83,6 +83,11 @@ void DeleteVisibleTrain(Train *v);
 void CheckBreakdownFlags(Train *v);
 void GetTrainSpriteSize(EngineID engine, uint &width, uint &height, int &xoffs, int &yoffs, EngineImageType image_type);
 
+inline int GetTrainRealisticBrakingTargetDecelerationLimit(int acceleration_type)
+{
+	return 120 + (acceleration_type * 48);
+}
+
 /** Variables that are cached to improve performance and such */
 struct TrainCache {
 	/* Cached wagon override spritegroup */

src/train_cmd.cpp

@@ -1030,7 +1030,8 @@ void Train::UpdateAcceleration()
 				break;
 
 			case AM_REALISTIC: {
-				bool maglev = this->GetAccelerationType() == 2;
+				int accleration_type = this->GetAccelerationType();
+				bool maglev = (accleration_type == 2);
 				int64 power_w = power * 746ll;
 				int64 min_braking_force = this->gcache.cached_total_length * 300;
 				if (!maglev) {
@@ -1072,7 +1073,7 @@ void Train::UpdateAcceleration()
 				}
 				min_braking_force -= (min_braking_force >> 3); // Slightly underestimate braking for defensive driving purposes
 				this->tcache.cached_uncapped_decel = Clamp(min_braking_force / weight, 1, UINT16_MAX);
-				this->tcache.cached_deceleration = Clamp(this->tcache.cached_uncapped_decel, 1, 120);
+				this->tcache.cached_deceleration = Clamp(this->tcache.cached_uncapped_decel, 1, GetTrainRealisticBrakingTargetDecelerationLimit(accleration_type));
 				break;
 			}
 		}