One way to model train operations and make predictions of future outcome is to use simulation. Many lines and networks connecting major cities have a high capacity utilization, meaning that running additional trains leads to an even more strained situation and delays are likely to increase. The mix of average train speeds is also related to capacity and delay propagation.
Considering one line or several lines connected in a network a requested train traffic can consist of different train categories and departure frequencies. There are usually several possible timetables satisfying this traffic demand. The infrastructure often implies limitations on the type and volume of traffic that can be handled. Additionally constraints introduced by requests for regular intervals, minimum headways, passenger transfers between trains etc. can reduce the number of acceptable timetables.
This paper presents an approach using combinatorial train initiations and simulation to generate conflict-free timetables. These can then be simulated with random variations in departure and dwell times. This is implemented on a fictive single track line with high speed passenger train traffic. The objective is to study outcome by varying allowance times and delays. Simulations are carried out in RailSys, a software using synchronous simulation to model train traffic operations.