How are train schedules made?

I've ridden both the LIRR and the MNR (two primary commuter railroads of Greater New York) and their schedules are usually very accurate. How do they make them? Led alone make them so accurate? Do you use software? Who usually makes the schedule?

The schedules determine when the trains run so that's why they are accurate.

It involves a lot of work, calculating traveling times, dwell times (to load passengers), and then dealing with the physical plant which includes managing trains having to change tracks, multiple routes sharing one line (Ronkonkama, Oyster Bay, West Hempsted all share the LIRR Minline), dealing with other railroads (especially when they own the railroad) and when you can have time in major stations.

Then you have to survey demand to see when your trains are needed, and how to manage equipment and staff schedules.

frischee112 wrote:I've ridden both the LIRR and the MNR (two primary commuter railroads of Greater New York) and their schedules are usually very accurate. How do they make them? Led alone make them so accurate? Do you use software? Who usually makes the schedule?

There is a variety of software out there which allows creation of accurate train schedules. Most include some type of Train Performance Calculator (TPC), a software-based simulation model which can be used to accurately predict train travel times by taking into account the physical plant (lengths of links between stations and other points, speeds, curvature - both horizontal and vertical, etc.), and equipment characteristics and performance (acceleration and deceleration, weight, physical dimensions like frontal area, etc.).

Once those raw travel times are determined, survey data is normally used to establish minimum and scheduled dwell times at stations. Finally, the whole thing is assembled into a coherent schedule using conflict-detection routines (which can be pretty sophisticated, or very basic - a time/distance string chart, for example).

The schedules are normally made by a rail operations planning department, which normally has responsibility to produce the revenue and non-revenue timetables, equipment plans (including fuel moves, equipment cycling, and so forth), and crew plans. The department will also normally include the provision of special timetables for track outages, work programs, and so forth.

My impression, based on riding Metro-North regularly for the past 20+ years, is that there is also some fine tuning based on experience with the previous schedule.

Typically, if there's a significant change one schedule, such as adding a train, or adding a stop, or some rerouting due to long-term track work, the next schedule will adjust various time points by a minute or two, based on whether the train was consistently late or early to that stop. Some of the comments from M-N on the schedule changes seem to support that view, too.

Yeah; there's always fine tuning and unforeseen issues.

Maybe your allotted 1 minute to load passengers at a station; but you have an unusual spike in ridership and you need 5 minutes. Maybe multiple handicapped persons needing assistance are there.

Maybe it rained and the wheels aren't getting good traction so you have to go a little slower.

It's an art and a science