Buffer Time Optimization in the Function of Timetable Stability


  • Branimir Duvnjak HŽ Infrastruktura d.o.o.
  • Tomislav Josip Mlinarić University of Zagreb, Faculty of Transport and Traffic Sciences
  • Danko Kezić University of Split, Faculty of Maritime Studies




simulation modelling, Petri net, buffer time, headway, traffic optimisation, traffic segmentation


Timetable stability depends on the regularity of trains. Any deviation from the planned timetable leads to its instability. Railway network characteristics determine the capacities of the transport service. Depending on the capacity calculation method, time components are added to the minimum headway to ensure timetable stability. The UIC 405 method is simple and can be used on all railways. The disadvantage is that the calculations are based on average data. According to the method, the minimum headway consists of the time of the average headway interval, additional time and the buffer time. The additional time is precisely defined by the number of APB sections, while the buffer time is in the average value. When creating the timetable, the goal is optimal utilisation of the infrastructure. If the headway is too long, the capacity is not used, and if it is too short, timetable instability will ensue. Instead of averaging, this work calculates a buffer time that depends on the ratio of the travel time of the previous and the following trains. In this way, the headway is optimised and the calculation of the UIC 405 method is improved.


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How to Cite

Duvnjak, B., Mlinarić, T. J., & Kezić, D. (2023). Buffer Time Optimization in the Function of Timetable Stability. Promet - Traffic&Transportation, 35(4), 514–524. https://doi.org/10.7307/ptt.v35i4.13