EXTENDING THE CAPACITY OF HIGHLY USED INNER CITY RAIL LINKS



EXTENDING THE CAPACITY OF HIGHLY USED INNER CITY RAIL LINKS

Authors

Dr. Raphaela Rudolph, IVEmbH

Description

As populations grow operators of railbound transport face the task of extending supply while the options of extending infrastructure are limited. The paper describes how to extend the capacity without extending tracks and how to model these methods.

Abstract

As the populations grow in the cities operators of railbound transport face the task of extending their supply while the possibilities of extending their infrastructure are rather limited.
The situation is similar in many cities all over the world: The populations grow and as the individual traffic often collapses during rush hours, the demand for public transport increases rapidly. At the same time the infrastructural extension of rail capacity by building new tracks or completely new lines is often impossible because every square inch of ground in the city centres is already put to use. Even underground extensions are just not possible or considering all still too expensive. For these reasons inner city rail operators no matter if tram, metro or subway face the task of extending their traffic volume without being able to extend their tracks.
There are various possibilities of non-constructional capacity extensions depending on the restricting elements of the respective system. While in some systems the traffic throughput may be increased by just adding signals at strategic locations or changing time-consuming operational procedures other systems may need to exchange their signalling system altogether and install new technologies featuring continuous transfer of signalling information or moving block operation as used e.g. in ETCS level 2 or 3.
Though not necessarily as costly as building new tracks the implementation of new signals or alternative operational procedures needs to be well investigated before being installed. Modelling railbound operation with the help of operational simulation has proved to be a valuable method to investigate such problems. Being able to model railway systems of a whole country there are no restrictions in modelling suburban transport whatsoever. The results such as on time running, delay development, recovery times, optimised headways, and many more can easily be delivered for different model setups. They help the operator to compare different solutions and make educated decisions about the implementation of costly enhancements.
The city rail operators of Hamburg, Hanover and Munich (amongst others) have had their operation investigated and optimised with such models. Although all German these three cities have been considering different solutions to similar problems. This paper describes the different approaches to increase capacity and displays different methods of evaluation and presentation of modelling results according the operator’s needs.

Publisher

Association for European Transport