Signal System Varieties

The LIRR employs a number of different signaling system types across the system.  These types of signaling systems (which are rooted and defined in the LIRR's operating rules) govern train movements in different ways.  The table below shows which variety of signal system is used on the respective part of the system.  Note that this is different from LIRR's wayside signal indications, which are the instruments by which train movements governed by the below rules are communicated to train crews.  While the LIRR also has a number of different varieties of wayside signal types, at the end of the day they all communicate a consistent message, and shouldn't be confused with the signal system varieties defined in the rules below.

Each of the segments of track below has two properties in the right columns.  The first indicates whether there is speed control in use along that segment, the second indicates the type of signals used to convey indications to train crews (either wayside for physical signals along the right of way, cab signals, or manual block in the event of no physical or cab signals).  Note that in several cases, different systems are in place depending on the track or direction.  In these cases, normal direction refers to the direction of movement established for a particular track (e.g. eastbound, westbound).  Reverse is the opposite way. Generally, LIRR trains operate on the right-hand side.

Note that the conventions below generally apply to sections of mainline track only, outside of interlocking limits.  Within interlocking limits, different rules may apply (generally, all movements are controlled by wayside signals, except at Y and LOCUST).

Updated March 2021

Branch	from...	...to	Tracks	Direction	Speed control	Train spacing
Amtrak	JO/C	HAR	All	Both	ASC + ACSES II	Wayside (409)
Atlantic	BR1	ENI	All	Normal	ASC + ACSES II	Wayside (409)
Atlantic	BR1	ENI	All	Reverse	ASC + ACSES II	Cab signals (410)
Atlantic	ENI	DUN	All	Both	ASC + ACSES II	Wayside (409)
Atlantic	DUN	JAY	All	Both	ASC + ACSES II	Wayside (409)
Atlantic	HAL	VAL	All	Both	ASC + ACSES II	Cab signals (410)
Central	BTH	BAB	All	Both	ACSES II only	Wayside (ABS)
Far Rockaway	VAL	FRY	All	Normal	ASC + ACSES II	Cab signals (410)
Far Rockaway	VAL	FRY	All	Reverse	ACSES II only	Manual Block (CMB)
Hempstead	QNS	GDN	All	Both	ASC + ACSES II	Cab signals (410)
Hempstead	GDN	HEM	All	Both	ASC + ACSES II	Wayside (409)
Long Beach	VAL	LED	All	Both	ASC + ACSES II	Cab signals (410)
Main Line	HAR	JAY	1, 2	Both	ASC + ACSES II	Wayside (409)
Main Line	HAR	JAY	3, 4	Normal	ASC + ACSES II	Wayside (409)
Main Line	HAR	JAY	3, 4	Reverse	ASC + ACSES II	Cab signals (410)
Main Line	JAY	HAL	0-9	Both	ASC only	Wayside (409)
Main Line	HAL	PND	All	Both	ASC + ACSES II	Cab signals (410)
Main Line	PND	KO	All	East	ASC + ACSES II	Cab signals (410)
Main Line	PND	KO	All	West	ASC + ACSES II	Wayside (409)
Main Line	KO	GPT	All	Both	ACSES Lite	Manual Block (MBS)
Montauk	HAL	BAB	All	Both	ASC + ACSES II	Cab signals (410)
Montauk	BAB	Y	All	Normal	ACSES II only	Wayside (ABS)
Montauk	BAB	Y	All	Reverse	ACSES II only	Manual Block (MBS)
Montauk	Y	PD	All	Both	ACSES II only	Manual Block (CMB)
Montauk	PD	MTK	All	Both	ASC + ACSES II	Cab signals (410)
Oyster Bay	NAS	LOC	All	Normal	ACSES II only	Wayside (ABS)
Oyster Bay	NAS	LOC	All	Reverse	ACSES II only	Manual Block (MBS)
Oyster Bay	LOC	OBY	All	Both	ACSES II only	Manual Block (CMB)
Port Jefferson	DIV	HUN	All	Both	ASC + ACSES II	Cab signals (410)
Port Jefferson	HUN	JEF	All	Both	ASC + ACSES II	Cab signals (410)
Port Washington	HAR	WOD	All	Normal	ASC + ACSES II	Wayside (409)
Port Washington	HAR	WOD	All	Reverse	ASC + ACSES II	Cab signals (410)
Port Washington	WOD	PWS	All	Both	ASC + ACSES II	Cab signals (410)
West Hempstead	VAL	WHD	All	Both	ASC + ACSES II	Cab signals (410)

Speed control:

• ASC (rules 400-408 and 411-412): Automatic Speed Control in place to regulate train speeds
• ACSES II: LIRR's implementation of Positive Train Control
• ACSES Lite: a reduced functionality version of Positive Train Control installed on the North Fork ("ACSES Lite" is not a technical term, but used to refer to the LIRR's application of ACSES II in conjunction with procedural changes in Manual Block territory).

Signal types types:

• Wayside (rule 409): train spacing regulated by wayside signals
• Wayside (ABS): Automatic Block Signaling, train spacing regulated by wayside signals
• Cab signals (rule 410): train spacing regulated by cab signals
• Manual Block (CMB): Controlled Manual Block, used only where there are no locations where trains can pass each other between the starting and ending point, permission to enter block given by setting the signals at the beginning of each segment
• Manual Block (MBS): Manual Block Signaling, train spacing regulated by fixed block signals that may only be passed with written permission

Generally, all of the LIRR's freight-only lines (the Bay Ridge Branch, Bushwick Branch, C Secondary, etc.) are unsignaled, as well as most freight sidings and spurs (like NYAR's Calverton Spurs).  Most of the freight-only territory is dispatched by New York & Atlantic Railway and governed by their own book of rules (similar to the GOCR standard).  The Lower Montauk Branch from JAY to BLISS was previously governed by wayside signals in the normal direction and MBS in the reverse prior to the discontinuation of passenger service in 2012.  Since then, LIRR has downgraded the line to secondary track, and retired the wayside signaling system.  It is now operated and dispatched by NY&AR under their operating rules.

This list was correct at the time of publication, however changes may happen has the railroad continues to upgrade its signal system, especially with the installation of Positive Train Control, which will be installed in most locations that see passenger service, except those noted here.