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These signals are normally unlit (displaying no aspect), unless a route towards the signal has been set, or a train is standing on the berth track circuit for the signal.

They are used where same direction movements can take place on parallel lines, but where the main line has no corresponding signal.

The use of approach lit signals fell out of favour for new installations in the 1990s, but has again been permitted since 2003.

Most remaining approach lit signals in England were converted to continuously lit in the 1990s, one remains in the Gloucester area (G121, Haresfield Down Goods Loop), and another exists at Rickmansworth on the shared Metropolitan/Chiltern route.

A novel use of an approach lit signal was commissioned at Midcalder Junction in May 2013, when the Junction was re-doubled.
Bi-directional capability was retained on the Down Shotts connection, whilst the former Goods Loop became part of the Up Shotts.
Signal EJ720 on the Up Shotts is a 3-aspect (R/Y/G) stop signal, but a parallel signal on the Down shotts, EJ718, is an approach lit 2-aspect (Y/G) distant signal.

This has been done to avoid EJ718 having a red aspect that is not requred to control train movements, but may have caused confusion with respect to the old layout.

A list of Approach Lit Signals in Scotland.

Signal	Location	Direction	Year installed	Remarks
	Highland Main Line, controlled from Aviemore S.B.
AK304	Kincraig Loop	Up	1979
AK305	Kincraig Loop	Down	1979
AC334	Carrbridge Loop	Up	1979	138y from end of platform 2.
AC335	Carrbridge Loop	Down	1979	Platform 2
AS344	Slochd Summit Loop	Up	1979
AS345	Slochd Summit Loop	Down	1979
AT354	Tomatin Loop	Up	1980
AT355	Tomatin Loop	Down	1980
AM364	Moy Loop	Up	1979
AM365	Moy Loop	Down	1979
	Controlled from Edinburgh S.C.
EB671	Ladybank, Branch Loop	Down	1980
EV426	Inverkeithing Up Passenger Loop	Up	1979
EY655	Dalmeny, Up Passenger Loop	Down	1979	Fixed red, ground level.
EY657	Dalmeny, Down Passenger Loop	Down	1979
EP624	Powderhall Branch Junction	Up	1989?	Adjacent to ECML
EN583	Bathgate Freight line	Down	1986	Removed Oct. 2008
EN2043	Bathgate station, Up line	Down	2010	Fixed Red, for reversing trains. Signalling Plan.
EJ718	Midcalder Junction, Down Shotts	Up	2013	Distant Signal, parallel with EJ720.
	West Coast Main Line, controlled by Motherwell S.C.
M155	Newton, Down South Goods Loop	Down	1973	Removed 1991.
M146	Newton, North Connecting Line	Up	1991	Changed to continuously lit, 1994?
M165	Newton, South Connecting Line	Down	1991	Changed to continuously lit, 1994?
MC410	Ravenstruther, Down Main	Up	1989?	Access to Coal Terminal
MC410R	Ravenstruther, Down Main	Up	1989?	Distant for MC410
	Larkhall Branch, controlled from Motherwell S.C.
MH705	Allanton Loop	Up	2005
MH706	Allanton Loop	Down	2005
	Controlled by Paisley S.C. (controlled from West of Scotland S.C. from 27/12/2011)
GPD133	Dunrod Loop (Wemyss Bay branch)	Down	1967	Originally P133
GPH523	Hunterston, Low Level Loop	Down	1978	Adjacent to Largs Branch
GPK222	Kilwinning, Up Goods Loop	Up	1986
PE148	Elderslie Passenger Loop	Up	1985	Removed Nov. 2009
	Controlled by Yoker IECC
YC638	Craigendoran, West Highland Loop	Up	1984
YC639	Craigendoran, West Highland Loop	Down	1984
YS164	Coatbridge Sunnyside, platform 1	Down	1991	Fixed red, for reversing trains
	Alloa - Kincardine, controlled by the Stirling - Kincardine Panel.
SK6553	Alloa Loop	Down	2008	Signalling Plan
	Controlled by Annan S.B.
AN15	Annan, Platform 2, Down Line	Up	2008	Fixed Red, for reversing trains
	Barrhead - Kilmarnock, controlled by Lugton S.B.
LU2	near Stewarton, Down Line (17m 75c)	Down	2009	Bi-directional lines. Signalling Plan
	East Kilbride Branch, controlled from West of Scotland S.C.
GB5130	Hairmyres Loop	Up	2013
GB5131	Hairmyres Loop	Down	2013