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Rail Network Capacity

Rail Network Capacity (RNC) or UIC405 method​

The RNC is a restricted, client-specific add-on which executes a network-wide calculation of the capacity using the timetable-independent method according to the standard UIC 405.

The Rail Network Capacity (RNC) module employs the UIC 405 approach to estimate the capacity of railway lines. This is achieved by utilizing headway times automatically derived from the blocking times of trenissimo.

The RNC algorithm operates through three key steps:

  1. Division of network into lines.
  2. Calculation of headway times. For each line, the critical section is identified (the section with longest headway times).
  3. Capacity calculation.

Install the required trenissimo plugin

In order to use the "Rail Network Capacity" module in trenissimo, it is necessary to install the plugin, following the installation procedure for the additional features:

  • From the Tools Menu, click Plugins. The Plugin dialog will open.
  • Click the Available Plugins tab.
  • Optionally, click Check for Newest to load the most up-to-date list of plugins.
  • Click the Install checkbox to select the plugin "Rail Network Capacity" to install.
  • Click Install and follow the procedure.
  • Restart trenissimo before start using the installed feature.

Principles used for calculating capacity and the number of trains (thus, utilized capacity) with the UIC 405 method

  • A 'line' is defined as a section between two stations of the network (line division of the network);
  • A 'section' is defined as the part of the line between any pair of consecutive stations (or junctions) of each 'line';
  • The capacity is calculated according to the UIC 405 method;
  • The number of trains in a 'line' is the number of trains entering the critical 'section' of the 'line';
  • The capacity of a 'line' is the minimum capacity of each 'section' of the 'line'.

Division of Network into Lines

The network is automatically divided into lines, i.e. the relevant stations which will be the start/end points of lines for the UIC405 are found.

  1. All stations that separate single from double track sections are kept;
  2. The non-junction stations without trains starting/ending are removed;
  3. If there are 4 (or more) pairs of edges [ex: 4 track line] check if the station can be divided as separated stations (no trains going from 1 line to the other). If yes, the station is divided into “virtual stations”: each of these can be start/end of a line passing there.
  4. All stations in which >10% of the trains (that are there) start/end are kept.

Calculation of Headway Times

The Mean Headway time is the minimum headway time of all train groups on the critical section of the line, weighted by the number of services of each group. In order to identify the critical section, the mean headway time is estimated automatically on all sections of the line, and the one with the highest value considered in the outputs.

The Mean Headway time tfm is calculated through the following formula:

drawing

Where:

i = First Train group

j = Second Train group

ni nj = N trains/day in each group

tfij = minimum headway time between i and j

Notes:

  • i, j are all train groups (thus also the headway time between two trains of the same group is considered;
  • On Single Track, the two directions are considered together;
  • On Double Track the two directions are separated and the maximum is considered.

Capacity Calculation

The capacity is calculated according to the following formula:

Capacity = Time Unit / (Headway + Buffer + Supplement)

Where:

  • Time Unit = By default 24 hours (1440 min), user-definable
  • Buffer = 0,67 * Headway [daily]
  • Buffer = 0,33 * Headway [Peak hour]
  • Supplement = N sections * 0,25

Using the RNC in trenissimo

To use the module "Rail Network Capacity" in trenissimo, the plugin is required to be installed.

To prepare the trenissimo simulation please follow the steps to export a timetable from TrenoLive to trenissimo.

The "Rail Network Capacity - UIC 405" settings window can be opened with right-click on any already prepared trenissimo simulation.

  • From the "Rail Network Capacity - UIC 405" settings window you can select the Mode (Daily/Peak Hour), buffers, margins, start and end times.
  • Click on Finish to run the calculation.
  • The outputs can be found in the simulation Outputs folder with the names uic405.csv and uic405headway.csv.

Outputs

The uic405headway.csv file contains the list of calculated headway times between all train groups on all sections.

The uic405.csv file contains the the number of trains running on that line / the max number of trains (capacity) / the % capacity utilisation (ratio between the two previous numbers).