The West Hempstead Branch is the Long Island Rail Road’s shortest and least used full-time branch (Belmont Park, operated on race days only is shorter) with just 3,320 daily passengers (half of the next lowest branch, the Oyster Bay Branch). The entirely single-tracked branch stretches for 4.6 miles curving northeast off the Montauk Branch just after Valley Stream ending with a two-track yard (tracks named Fence and Long) just south of the West Hempstead branch main line with one of the siding tracks stretching to just before the Hempstead Gardens Station, although there is just one interlocking just before the island platform of the West Hempstead Station, making this track not usable as a passing siding.
The branch was electrified via third rail in 1926 and originally service extended north from West Hempstead, connecting to the Hempstead Branch at Country Life Press, and ending at the Main Line in Mineola, forming a central Nassau county loop. Passenger operations on the line beyond West Hempstead were eliminated in 1935 because of new requirements from the Public Service Commission for grade-crossing eliminations, and this line was abandoned for freight operations in the 1960s.
The branch was the last in electric territory to receive High-level platforms in 1970s to allow high-level only M1s to operate across all electric territory. The fact the branch is still in operation is a testament to the fact that the Long Island Rail Road became the first publicly owned commuter railroad when the state of New York purchased it (forming the Metropolitan Commuter Transit Authority) from the Pennsylvania Railroad in 1965. This meant unlike the other legacy commuter railroads, the Pennsylvania Railroad had not started abandoning lower ridership lines, before operations were taken over by the state. The line has been proposed for abandonment by the MTA on several occasions during budget crises (including during the 2009 Great Recession) and between September 18, 2010 and November 22, 2014 all weekend service on the branch was discontinued, with trains operating during weekdays only.
Service on the line during off peak hours and on weekends consists of a shuttle trainset of M7s operating every 2 hours between West Hempstead and Valley Stream, these shuttle trains take 15 minutes to transverse the branch one-way (30 minutes round-trip) and sit three-quarters of their remaining time. There is zero reason why hourly service cannot be provided on the branch hourly since the trainset is otherwise just sitting on the siding tracks near West Hempstead or Valley Stream. The three person crew (all LIRR trains are required to have an engineer, conductor, and assistant conductor, per union contracts; Metro-North is allowed to operate with just 2 person crews) are on the clock sitting, not providing train service. At Valley Stream the shuttle trains connect with either Far Rockaway Branch trains to and from Atlantic Terminal (including all weekend service, it takes 2 transfers to get to Penn Station) or on weekdays some trains connect with Long Beach Branch trains to and from Penn Station.
During Peak Hours trains are extended to Jamaica and into Atlantic Terminal, plus of the March 29, 2021 schedule, one AM train runs from West Hempstead to Penn Station, with no reverse PM peak train (pre COVID-19 schedule changes there was one PM peak train).
St. Albans is also included in West Hempstead Branch timetables. This outlier of a station is the only one on the Montauk Branch in Queens between Jamaica and Valley Stream where the branch is separate from the Atlantic Branch (normally used by Long Beach and Far Rockaway branch trains) and sees service only from West Hempstead branch trains during the AM peak hour inbound to Atlantic Terminal or Penn Station. Otherwise, all service is provided by Babylon Branch trains, hourly (or better) on weekdays, and only every 2 hours on Weekends. These trains get a special Via St. Albans sign on the track information screens at Jamaica (and I believe at other western terminals)