What is a railway timetable?
In general, a railway timetable contains information such as departure time, arrival time, dwell time (stop time) at a station. A passenger refers to the timetable to know when the train is arriving while a driver has a timetable (with more data in it) to know how fast to drive and when to arrive/depart at a station.
Why timetable planning?
A good timetable for railway operation is a timetable that provides just enough buffer to the trains, flexible and robust enough to adapt to delays and frequent and punctual enough to the passengers.
Therefore, a timetable shall be planned and verified before being implemented in production.
Timetable planning can be done for the long and immediate future.
Long term planning
To bring better services to the passengers and freight companies, infrastructure managers (IM) and railway operating companies (ROC) normally plans far ahead. To achieve better services, there might be new tracks to build to increase capacity, new trains to be procured to attain the required passenger per hour per direction (pphpd), new flyovers to be constructed to reduce bottleneck issues at junctions or even new lines and stations to be introduced to improve connectivity.
By doing timetable planning, all these requirements to achieve long term goals can be determined.
Immediate term planning
Then, when it comes to immediate term, with existing trains and infrastructure, timetable planning is carried out to prepare yearly timetables. In a yearly timetable, trains will be assigned operating days such as weekend or weekday trains.
Nevertheless, a yearly timetable can also be subjected to variations. A track taken out temporarily for maintenance or even adding extra trains into the timetable for a special occasion (festive celebrations/ sport events/ concerts etc.), timetable planning is flexible enough to make these changes using the remaining train paths* available.
* Train path: A section of a track reserved for a train to run for a specific period of time. It is also known as timeslot.