FASTA is a comprehensive software package for the simulation of trains running on a network and timetable stability analyses.
It has been developed to analyse the behaviour of the timetable structure on a network scale. FASTA points out the evolution of delays and their geographic distribution. It uses a database describing infrastructure and timetables of the different lines.
The software has been developed by the Laboratory of Intermodality, Transport and Planning (LITEP) of the Swiss Federal Institute of Technology Lausanne (EPFL), in cooperation with the Swiss Federal Railways (SBB).

FASTA has been designed to:
? identify and analyse delays on a network level,
? detect causes of delays,
? show the geographical distribution of delays.

The software provides the user with the following outputs:
? delay diagrams with regard to the importance of the different nodes, different lines and different train categories,
? geographical delay diagrams for each hour of operation.

FASTA is based on the following concept:
? it's an event controlled discrete simulation tool, events being arrival and departure of trains in nodes,
? FASTA simulates a timetable operated on a given network, on the basis of the description of network (lines and nodes) and trains,
? the simulation takes into account network specific constraints, such as minimal headways and connections between trains at stations,
? FASTA runs in deterministic mode (running times of trains are set) or in stochastic mode (running times of trains are taken from a running time distribution function),
? inputs and results are stored in specific databases and may be exported.


The rail network is modeled using the classical graph theory concepts. Nodes are stations in the network and arcs are sections between stations. Each section has a specified number of physical tracks. A physical track section has a parameter defined which specifies the direction of traffic movement allowed for the track. Routes of trains are modeled as paths in the graph which consists of a sequence of sections in the network. The exact routing of the trains is determined dynamically during simulation of train-runs.

The model includes the following station types:
? connection stations: connections between trains are modeled,
? stop stations: stations where trains stop,
? crossings: points in the network where routes of two lines intersect,
? virtual stations: used for modeling network details and exceptions.


A network section is made up of physical tracks and is modeled using the number of physical tracks that it is made up of and the directions of traffic that each track is capable of handling.
All trains which perform the same service are grouped in train-families.

The timetable consist of arrival, departure and through times of all trains entered into the system. Using the timetable information, the model generates a train connection list based on a simple set of expert rules

The model generates a rotation plan similar to connections except that the rules are simpler.
According to a traffic control policy set by the timetable planner, trains wait for their connections.

FASTA provides two types of results:
? global statistical results depicted as graphs,
? detailed alphanumerical results.


The global statistical results allow a fast analysis of the system functioning in order to detect critical zones and periods for stability. Results are mainly depicted as delay histograms:
? histogram of delay in a node for several periods,
? histogram of delay for a period in several nodes,
? histogram of delays for all sections.


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The model permits as well a graphical visualization of the evolution of delays in the whole network. This visualization includes the following representations of delays:
? for each section,
? for arrival at the node,
? for departure at the node.


Delays are represented in form of a delay function which are generated during the period under consideration. Those functions could be: delay maximum or minimum, average delay, most or least frequent delay.




The detailed alphanumerical results permit detection of critical zones for the emergence, aggravation and propagation of delays in the network. These results allow an even more in-depth analysis of delay evolutions in the different zones.




FASTA is used to evaluate rail timetables. It can be of help with the :
? analysis of the stability of a cyclic timetable under a stable or disrupted regime,
? comparison of different traffic control policies,
? analysis of the consequences of maintaining connections on the timetable stability,
? fixation of running time buffers as well as their geographical distribution which are needed to guarantee timetable stability,
? analysis of track maintenance effects on the timetable stability of the network.


The results provided by the FASTA model help in the statistical macro-analysis of delays in the network as well as in the detailed analysis of delays and their causes. The main results are:
? delay histograms shown by delay-causes, timetable periods or by importance, in a node, on a line, in the network, for one or more train categories,
? geographical distribution of delays in a region or for the entire network,
? development of this distribution in the network on an hourly basis,
? a detailed evolution of the functioning of the network over time.