LIRR Jamaica-Valley Stream Routing

On the LIRR maps it shows the Babylon and West Hempstead branches being routed via St. Albans and the Far Rockaway and Long Beach branches being routed via Locust Manor. Do these lines always go via their route on the map or do expresses sometimes use the opposite line?

I believe Rockaway trains MUST go via Locust Manor. (Checked. They don't have to.)

Some Babylon trains are scheduled to go via Locust Manor. Some seem to go either way, Some despite never stopping at St. Albans, reliably go via St. Albans anyway. I do not have enough experience with Long Beach trains to answer with regards to them.

If a West Hempstead train makes Valley Stream, it is generally running via Locust Manor.

The switches at Valley are clumsy, but all the moves are possible if you don't mind crossing ahead of other trains, etc.

Under normal circumstances most Long Beach/Far Rockaway trains go via Locust Manor and Babylon/West Hempstead via St Albans. There are some cases of Babylon/West Hempstead via Locust Manor, especially at the height of rush hour, but Long Beach/Far Rockaway via St Albans is only done as an on the fly reroute when there's a problem on the other line.

Thanks. What about the Montauk Branch? Do trains listed as having no stops between Babylon and Jamaica go via the Babylon Branch or Main Line usually? Is it the same every day for certain trains or does it vary? Also, do Montauk Branch trains operating via the Babylon Branch operate via St. Albans, Locust Manner, or either?

1. More likely than not the Babylon Branch but can be either from what I've seen.

2. Unless there's a disruption somewhere (track work) the same trains will take the same routing every time it runs.

3. Montauk branch trains could operate either via St. Albans or Locust Manor with the application of answer 2.

If you can find a LIRR employee timetable somewhere out there on the interwebs many of the answers can be found within. Back when I was 12 or so I figured a lot of this out using all the old paper timetables available at the time and even drew up a chart.

You can also get the .pdf of the Montauk Branch timetable from the LIRR and figure if the train stops in either Mineola or Hicksville that it's traveling via the main line. I'd link to it here but since I'm traveling and can't figure out how to do so on an iPad I'll have to leave you to the Google.