diff --git a/src/newgrf.cpp b/src/newgrf.cpp
index 6049366299..1978e0ca6a 100644
--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -4465,7 +4465,7 @@ static ChangeInfoResult RoadTypeChangeInfo(uint id, int numinfo, int prop, ByteR
 	ChangeInfoResult ret = CIR_SUCCESS;
 
 	extern RoadTypeInfo _roadtypes[ROADTYPE_END];
-	RoadType *type_map = (rtt == RTT_TRAM) ? _cur.grffile->tramtype_map : _cur.grffile->roadtype_map;
+	std::array<RoadType, ROADTYPE_END> &type_map = (rtt == RTT_TRAM) ? _cur.grffile->tramtype_map : _cur.grffile->roadtype_map;
 
 	if (id + numinfo > ROADTYPE_END) {
 		GrfMsg(1, "RoadTypeChangeInfo: Road type {} is invalid, max {}, ignoring", id + numinfo, ROADTYPE_END);
@@ -4595,7 +4595,7 @@ static ChangeInfoResult RoadTypeReserveInfo(uint id, int numinfo, int prop, Byte
 	ChangeInfoResult ret = CIR_SUCCESS;
 
 	extern RoadTypeInfo _roadtypes[ROADTYPE_END];
-	RoadType *type_map = (rtt == RTT_TRAM) ? _cur.grffile->tramtype_map : _cur.grffile->roadtype_map;
+	std::array<RoadType, ROADTYPE_END> &type_map = (rtt == RTT_TRAM) ? _cur.grffile->tramtype_map : _cur.grffile->roadtype_map;
 
 	if (id + numinfo > ROADTYPE_END) {
 		GrfMsg(1, "RoadTypeReserveInfo: Road type {} is invalid, max {}, ignoring", id + numinfo, ROADTYPE_END);
@@ -6000,7 +6000,7 @@ static void RailTypeMapSpriteGroup(ByteReader &buf, uint8_t idcount)
 
 static void RoadTypeMapSpriteGroup(ByteReader &buf, uint8_t idcount, RoadTramType rtt)
 {
-	RoadType *type_map = (rtt == RTT_TRAM) ? _cur.grffile->tramtype_map : _cur.grffile->roadtype_map;
+	std::array<RoadType, ROADTYPE_END> &type_map = (rtt == RTT_TRAM) ? _cur.grffile->tramtype_map : _cur.grffile->roadtype_map;
 
 	std::vector<uint8_t> roadtypes;
 	roadtypes.reserve(idcount);
@@ -8964,18 +8964,18 @@ GRFFile::GRFFile(const GRFConfig *config)
 	}
 
 	/* Initialise rail type map with default rail types */
-	std::fill(std::begin(this->railtype_map), std::end(this->railtype_map), INVALID_RAILTYPE);
+	this->railtype_map.fill(INVALID_RAILTYPE);
 	this->railtype_map[0] = RAILTYPE_RAIL;
 	this->railtype_map[1] = RAILTYPE_ELECTRIC;
 	this->railtype_map[2] = RAILTYPE_MONO;
 	this->railtype_map[3] = RAILTYPE_MAGLEV;
 
 	/* Initialise road type map with default road types */
-	std::fill(std::begin(this->roadtype_map), std::end(this->roadtype_map), INVALID_ROADTYPE);
+	this->roadtype_map.fill(INVALID_ROADTYPE);
 	this->roadtype_map[0] = ROADTYPE_ROAD;
 
 	/* Initialise tram type map with default tram types */
-	std::fill(std::begin(this->tramtype_map), std::end(this->tramtype_map), INVALID_ROADTYPE);
+	this->tramtype_map.fill(INVALID_ROADTYPE);
 	this->tramtype_map[0] = ROADTYPE_TRAM;
 
 	/* Copy the initial parameter list
diff --git a/src/newgrf.h b/src/newgrf.h
index 5a4d661721..56b90a0679 100644
--- a/src/newgrf.h
+++ b/src/newgrf.h
@@ -131,13 +131,13 @@ struct GRFFile : ZeroedMemoryAllocator {
 	std::array<uint8_t, NUM_CARGO> cargo_map{}; ///< Inverse cargo translation table (CargoID -> local ID)
 
 	std::vector<RailTypeLabel> railtype_list;       ///< Railtype translation table
-	RailType railtype_map[RAILTYPE_END];
+	std::array<RailType, RAILTYPE_END> railtype_map{};
 
 	std::vector<RoadTypeLabel> roadtype_list;       ///< Roadtype translation table (road)
-	RoadType roadtype_map[ROADTYPE_END];
+	std::array<RoadType, ROADTYPE_END> roadtype_map{};
 
 	std::vector<RoadTypeLabel> tramtype_list;       ///< Roadtype translation table (tram)
-	RoadType tramtype_map[ROADTYPE_END];
+	std::array<RoadType, ROADTYPE_END> tramtype_map{};
 
 	CanalProperties canal_local_properties[CF_END]; ///< Canal properties as set by this NewGRF