diff --git a/src/pathfinder/follow_track.hpp b/src/pathfinder/follow_track.hpp
index a61930ac15..db990501d4 100644
--- a/src/pathfinder/follow_track.hpp
+++ b/src/pathfinder/follow_track.hpp
@@ -160,7 +160,7 @@ struct CFollowTrackT
 
 			return false;
 		}
-		if (m_tiles_skipped == 0 && ((!IsRailTT() && !Allow90degTurns()) || (IsRailTT() && Rail90DegTurnDisallowed(GetTileRailType(m_old_tile), GetTileRailType(m_new_tile), !Allow90degTurns())))) {
+		if (m_tiles_skipped == 0 && ((!IsRailTT() && !Allow90degTurns()) || (IsRailTT() && Rail90DegTurnDisallowedTilesFromDiagDir(m_old_tile, m_new_tile, m_exitdir), !Allow90degTurns()))) {
 			m_new_td_bits &= (TrackdirBits)~(int)TrackdirCrossesTrackdirs(m_old_td);
 			if (m_new_td_bits == TRACKDIR_BIT_NONE) {
 				m_err = EC_90DEG;
diff --git a/src/pathfinder/npf/npf.cpp b/src/pathfinder/npf/npf.cpp
index 037e0d20f7..3ef430f965 100644
--- a/src/pathfinder/npf/npf.cpp
+++ b/src/pathfinder/npf/npf.cpp
@@ -844,7 +844,7 @@ static TrackdirBits GetDriveableTrackdirBits(TileIndex dst_tile, TileIndex src_t
 	trackdirbits &= TrackdirReachesTrackdirs(src_trackdir);
 
 	/* Filter out trackdirs that would make 90 deg turns for trains */
-	if (type == TRANSPORT_RAIL && Rail90DegTurnDisallowed(GetTileRailType(src_tile), GetTileRailType(dst_tile))) {
+	if (type == TRANSPORT_RAIL && Rail90DegTurnDisallowedTilesFromTrackdir(src_tile, dst_tile, src_trackdir)) {
 		trackdirbits &= ~TrackdirCrossesTrackdirs(src_trackdir);
 	}
 
diff --git a/src/pbs.cpp b/src/pbs.cpp
index 73b548430f..c992d9b84d 100644
--- a/src/pbs.cpp
+++ b/src/pbs.cpp
@@ -521,7 +521,7 @@ bool IsSafeWaitingPosition(const Train *v, TileIndex tile, Trackdir trackdir, bo
 
 	/* Check for reachable tracks. */
 	ft.m_new_td_bits &= DiagdirReachesTrackdirs(ft.m_exitdir);
-	if (ft.m_tiles_skipped == 0 && Rail90DegTurnDisallowed(GetTileRailType(ft.m_old_tile), GetTileRailType(ft.m_new_tile), forbid_90deg)) ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(trackdir);
+	if (ft.m_tiles_skipped == 0 && Rail90DegTurnDisallowedTilesFromTrackdir(ft.m_old_tile, ft.m_new_tile, ft.m_old_td, forbid_90deg)) ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(trackdir);
 	if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) return include_line_end;
 
 	if (ft.m_new_td_bits != TRACKDIR_BIT_NONE && KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
@@ -625,7 +625,7 @@ bool IsWaitingPositionFree(const Train *v, TileIndex tile, Trackdir trackdir, bo
 
 	/* Check for reachable tracks. */
 	ft.m_new_td_bits &= DiagdirReachesTrackdirs(ft.m_exitdir);
-	if (Rail90DegTurnDisallowed(GetTileRailType(ft.m_old_tile), GetTileRailType(ft.m_new_tile), forbid_90deg)) ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(trackdir);
+	if (Rail90DegTurnDisallowedTilesFromTrackdir(ft.m_old_tile, ft.m_new_tile, ft.m_old_td, forbid_90deg)) ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(trackdir);
 
 	if (HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits))) return false;
 
diff --git a/src/rail.h b/src/rail.h
index d9d1c88b22..2dfb1eebed 100644
--- a/src/rail.h
+++ b/src/rail.h
@@ -21,6 +21,7 @@
 #include "strings_type.h"
 #include "date_type.h"
 #include "signal_type.h"
+#include "rail_map.h"
 #include "settings_type.h"
 
 /** Railtype flags. */
@@ -366,6 +367,21 @@ static inline bool Rail90DegTurnDisallowed(RailType rt1, RailType rt2, bool def
 	return rt1_90deg || rt2_90deg;
 }
 
+static inline bool Rail90DegTurnDisallowedTilesFromDiagDir(TileIndex t1, TileIndex t2, DiagDirection t1_towards_t2, bool def = _settings_game.pf.forbid_90_deg)
+{
+	return Rail90DegTurnDisallowed(GetTileRailTypeByEntryDir(t1, ReverseDiagDir(t1_towards_t2)), GetTileRailTypeByEntryDir(t2, t1_towards_t2), def);
+}
+
+static inline bool Rail90DegTurnDisallowedAdjacentTiles(TileIndex t1, TileIndex t2, bool def = _settings_game.pf.forbid_90_deg)
+{
+	return Rail90DegTurnDisallowedTilesFromDiagDir(t1, t2, DiagdirBetweenTiles(t1, t2));
+}
+
+static inline bool Rail90DegTurnDisallowedTilesFromTrackdir(TileIndex t1, TileIndex t2, Trackdir t1_td, bool def = _settings_game.pf.forbid_90_deg)
+{
+	return Rail90DegTurnDisallowedTilesFromDiagDir(t1, t2, TrackdirToExitdir(t1_td));
+}
+
 /**
  * Returns the cost of building the specified railtype.
  * @param railtype The railtype being built.
diff --git a/src/train_cmd.cpp b/src/train_cmd.cpp
index afacfa3acd..991a4d8de9 100644
--- a/src/train_cmd.cpp
+++ b/src/train_cmd.cpp
@@ -2473,7 +2473,7 @@ static void CheckNextTrainTile(Train *v)
 			if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) {
 				/* If the next tile is a PBS signal, try to make a reservation. */
 				TrackBits tracks = TrackdirBitsToTrackBits(ft.m_new_td_bits);
-				if (ft.m_tiles_skipped == 0 && Rail90DegTurnDisallowed(GetTileRailType(ft.m_old_tile), GetTileRailType(ft.m_new_tile))) {
+				if (ft.m_tiles_skipped == 0 && Rail90DegTurnDisallowedTilesFromTrackdir(ft.m_old_tile, ft.m_new_tile, ft.m_old_td)) {
 					tracks &= ~TrackCrossesTracks(TrackdirToTrack(ft.m_old_td));
 				}
 				ChooseTrainTrack(v, ft.m_new_tile, ft.m_exitdir, tracks, false, nullptr, false);
@@ -2803,7 +2803,7 @@ static PBSTileInfo ExtendTrainReservation(const Train *v, const PBSTileInfo &ori
 			if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) break;
 		}
 
-		if (ft.m_tiles_skipped == 0 && Rail90DegTurnDisallowed(GetTileRailType(ft.m_old_tile), GetTileRailType(ft.m_new_tile))) {
+		if (ft.m_tiles_skipped == 0 && Rail90DegTurnDisallowedTilesFromTrackdir(ft.m_old_tile, ft.m_new_tile, ft.m_old_td)) {
 			ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
 			if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) break;
 		}
@@ -2865,7 +2865,7 @@ static PBSTileInfo ExtendTrainReservation(const Train *v, const PBSTileInfo &ori
 	while (tile != stopped || cur_td != stopped_td) {
 		if (!ft.Follow(tile, cur_td)) break;
 
-		if (ft.m_tiles_skipped == 0 && Rail90DegTurnDisallowed(GetTileRailType(ft.m_old_tile), GetTileRailType(ft.m_new_tile))) {
+		if (ft.m_tiles_skipped == 0 && Rail90DegTurnDisallowedTilesFromTrackdir(ft.m_old_tile, ft.m_new_tile, ft.m_old_td)) {
 			ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(ft.m_old_td);
 			assert(ft.m_new_td_bits != TRACKDIR_BIT_NONE);
 		}
@@ -3153,7 +3153,7 @@ static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir,
 		DiagDirection exitdir = TrackdirToExitdir(res_dest.trackdir);
 		TileIndex     next_tile = TileAddByDiagDir(res_dest.tile, exitdir);
 		TrackBits     reachable = TrackdirBitsToTrackBits((TrackdirBits)(GetTileTrackStatus(next_tile, TRANSPORT_RAIL, 0))) & DiagdirReachesTracks(exitdir);
-		if (Rail90DegTurnDisallowed(GetTileRailType(res_dest.tile), GetTileRailType(next_tile))) {
+		if (Rail90DegTurnDisallowedTilesFromDiagDir(res_dest.tile, next_tile, exitdir)) {
 			reachable &= ~TrackCrossesTracks(TrackdirToTrack(res_dest.trackdir));
 		}
 
@@ -3264,7 +3264,7 @@ bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
 	TileIndex     new_tile = TileAddByDiagDir(origin.tile, exitdir);
 	TrackBits     reachable = TrackdirBitsToTrackBits(TrackStatusToTrackdirBits(GetTileTrackStatus(new_tile, TRANSPORT_RAIL, 0)) & DiagdirReachesTrackdirs(exitdir));
 
-	if (Rail90DegTurnDisallowed(GetTileRailType(origin.tile), GetTileRailType(new_tile))) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
+	if (Rail90DegTurnDisallowedTilesFromDiagDir(origin.tile, new_tile, exitdir)) reachable &= ~TrackCrossesTracks(TrackdirToTrack(origin.trackdir));
 
 	bool res_made = false;
 	ChooseTrainTrack(v, new_tile, exitdir, reachable, true, &res_made, mark_as_stuck);
@@ -3942,7 +3942,7 @@ bool TrainController(Train *v, Vehicle *nomove, bool reverse)
 				TrackBits red_signals = TrackdirBitsToTrackBits(TrackStatusToRedSignals(ts) & reachable_trackdirs);
 
 				TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
-				if (Rail90DegTurnDisallowed(GetTileRailType(gp.old_tile), GetTileRailType(gp.new_tile)) && prev == nullptr) {
+				if (Rail90DegTurnDisallowedTilesFromDiagDir(gp.old_tile, gp.new_tile, enterdir) && prev == nullptr) {
 					/* We allow wagons to make 90 deg turns, because forbid_90_deg
 					 * can be switched on halfway a turn */
 					if (!(v->track & TRACK_BIT_WORMHOLE)) {
@@ -4746,7 +4746,7 @@ static bool TrainCheckIfLineEnds(Train *v, bool reverse)
 
 	/* mask unreachable track bits if we are forbidden to do 90deg turns */
 	TrackBits bits = TrackdirBitsToTrackBits(trackdirbits);
-	if (Rail90DegTurnDisallowed(GetTileRailType(v->tile), GetTileRailType(tile))) {
+	if (Rail90DegTurnDisallowedTilesFromDiagDir(v->tile, tile, dir)) {
 		bits &= ~TrackCrossesTracks(FindFirstTrack(v->track));
 	}