diff --git a/src/ai/api/ai_types.hpp b/src/ai/api/ai_types.hpp
index 2eb629aba3..7308a0452b 100644
--- a/src/ai/api/ai_types.hpp
+++ b/src/ai/api/ai_types.hpp
@@ -97,7 +97,7 @@ typedef uint16 StringID;     ///< The ID of a string.
 typedef uint16 SubsidyID;    ///< The ID of a subsidy.
 typedef uint32 TileIndex;    ///< The ID of a tile (just named differently).
 typedef uint16 TownID;       ///< The ID of a town.
-typedef uint16 VehicleID;    ///< The ID of a vehicle.
+typedef uint32 VehicleID;    ///< The ID of a vehicle.
 
 /* Types we defined ourself, as the OpenTTD core doesn't have them (yet) */
 typedef uint AIErrorType;    ///< The types of errors inside the NoAI framework.
diff --git a/src/ai/api/ai_vehicle.hpp b/src/ai/api/ai_vehicle.hpp
index 126503e216..083e9da1c1 100644
--- a/src/ai/api/ai_vehicle.hpp
+++ b/src/ai/api/ai_vehicle.hpp
@@ -97,7 +97,7 @@ public:
 		VS_INVALID = 0xFF, ///< An invalid vehicle state.
 	};
 
-	static const VehicleID VEHICLE_INVALID = 0xFFFF; ///< Invalid VehicleID.
+	static const VehicleID VEHICLE_INVALID = 0xFFFFF; ///< Invalid VehicleID.
 
 	/**
 	 * Checks whether the given vehicle is valid and owned by you.
diff --git a/src/cargopacket.h b/src/cargopacket.h
index dfd5e72d9c..77f656bcff 100644
--- a/src/cargopacket.h
+++ b/src/cargopacket.h
@@ -23,8 +23,8 @@
 typedef uint32 CargoPacketID;
 struct CargoPacket;
 
-/** Type of the pool for cargo packets. */
-typedef Pool<CargoPacket, CargoPacketID, 1024, 1048576, true, false> CargoPacketPool;
+/** Type of the pool for cargo packets for a little over 16 million packets. */
+typedef Pool<CargoPacket, CargoPacketID, 1024, 0xFFF000, true, false> CargoPacketPool;
 /** The actual pool with cargo packets */
 extern CargoPacketPool _cargopacket_pool;
 
diff --git a/src/script/squirrel.hpp b/src/script/squirrel.hpp
index 43aaa11fa0..ec9871d72f 100644
--- a/src/script/squirrel.hpp
+++ b/src/script/squirrel.hpp
@@ -85,6 +85,12 @@ public:
 	 */
 	void AddConst(const char *var_name, int value);
 
+	/**
+	 * Adds a const to the stack. Depending on the current state this means
+	 *  either a const to a class or to the global space.
+	 */
+	void AddConst(const char *var_name, uint value) { this->AddConst(var_name, (int)value); }
+
 	/**
 	 * Adds a const to the stack. Depending on the current state this means
 	 *  either a const to a class or to the global space.
@@ -126,6 +132,7 @@ public:
 
 	void InsertResult(bool result);
 	void InsertResult(int result);
+	void InsertResult(uint result) { this->InsertResult((int)result); }
 
 	/**
 	 * Call a method of an instance, in various flavors.
diff --git a/src/vehicle_base.h b/src/vehicle_base.h
index ea7d70baef..5b562db170 100644
--- a/src/vehicle_base.h
+++ b/src/vehicle_base.h
@@ -53,7 +53,8 @@ struct VehicleCache {
 	uint32 cached_var43; ///< Cache for NewGRF var 43
 };
 
-typedef Pool<Vehicle, VehicleID, 512, 64000> VehiclePool;
+/** A vehicle pool for a little over 1 million vehicles. */
+typedef Pool<Vehicle, VehicleID, 512, 0xFF000> VehiclePool;
 extern VehiclePool _vehicle_pool;
 
 /* Some declarations of functions, so we can make them friendly */
diff --git a/src/vehicle_type.h b/src/vehicle_type.h
index 7e28df10ab..dc283de16f 100644
--- a/src/vehicle_type.h
+++ b/src/vehicle_type.h
@@ -14,7 +14,7 @@
 
 #include "core/enum_type.hpp"
 
-typedef uint16 VehicleID;
+typedef uint32 VehicleID;
 
 /** Available vehicle types. */
 enum VehicleType {
@@ -45,7 +45,7 @@ struct BaseVehicle
 	VehicleTypeByte type;    ///< Type of vehicle
 };
 
-static const VehicleID INVALID_VEHICLE = 0xFFFF; ///< Constant representing a non-existing vehicle.
+static const VehicleID INVALID_VEHICLE = 0xFFFFF; ///< Constant representing a non-existing vehicle.
 
 /** Pathfinding option states */
 enum VehiclePathFinders {