Analysis of capacity on double-track railway lines

1. Analysis of capacity on double-track railway lines Olov Lindfeldt February 2008

2. Disposition • Introduction – freight capacity question • TVEM (model) • Infrastructure modeling • Application • - Three-pattern case • Conclusions

3. Freight capacity question • What is the capacity for freight traffic on existing lines if high speed lines are constructed? It depends on the timetable! Ways to find the timetable for 2050: • Assume one • Make more general assumptions an generate a large number of timetables Develop an algorithm that generates timetables and evaluate freight capacity as a distribution… Disregard disturbances (delays)

4. Freight capacity question • What is the capacity for freight traffic on existing lines if high speed lines are constructed? • It depends on the timetable! Ways to find the timetable for 2050: • Assume one • Make more general assumptions an generate a large number of timetables Develop an algorithm that generates timetables and evaluate freight capacity as a distribution… Disregard disturbances (delays)

5. Freight capacity question • What is the capacity for freight traffic on existing lines if high speed lines are constructed? • It depends on the timetable! • Ways to find the timetable for 2050: • Assume one • Make more general assumptions and generate a large number of timetables Develop an algorithm that generates timetables and evaluate freight capacity as a distribution… Disregard disturbances (delays)

6. Freight capacity question • What is the capacity for freight traffic on existing lines if high speed lines are constructed? • It depends on the timetable! • Ways to find the timetable for 2050: • Assume one • Make more general assumptions and generate a large number of timetables • Develop an algorithm that generates timetables and evaluate freight capacity as a distribution… • Disregard disturbances (delays)

7. Research view Aim • How do the infrastructure and the timetable affect capacity? Method • Combinatorial analysis of infrastructure designs and timetable structures. TVEM:Timetable Variant Evaluation Model

8. TVEM: Assumptions • Passenger traffic operated with a periodic timetable • Train patterns • All patterns are scheduled according to a priority order. • A train with higher priority is never given scheduled delay for a train with lower priority.

9. TVEM: Structure

10. TVEM: Variables • Run times between overtaking stations(infrastructure + vehicle) • Deceleration and acceleration supplements(for overtaking situations) • Regular stops • Track dispositions at stations • Frequency of service • Scheduling order

11. TVEM: Calculation scheme • Periodic timetable train patterns • Scheduling order for train patterns • Time step: 1 minute • Last pattern: as many freight trains as possible

12. Infrastructure modelling (1/2) • Real distribution for inter-station distance. • Fitted Weibull distribution (M-L). • Mean: 22,7 km Std: 109 km2.

13. Infrastructure modelling (2/2) • Effect of additional overtaking stations? • Halve the greatest distance repeatedly. relationship between parameters

14. Application: Three-pattern caseHigh-speed, regional and freight trains Mean number of trains (capacity): • Two speed combinations - 160/115 km/h (dotted) - 210/160 km/h (solid) • Two infrastructure layouts.Inter-station distance: - mean 22 km (lower) - mean 17 km (upper)

15. Conclusions • Combinatorial / deterministic approach  TVEM • Infrastructure treated as a variable. Modeled stochastically (replications) • Regular passenger timetable  train pattern  combinatorial timetable analysis • Evaluation: mean capacity, variance caused by: • Infrastructure • Timetable

16. Number of freight trains/h Thank You for the attention!