Planning and Prioritising Conventional and High-Speed Train Services
John Armstrong, Arup, University of Southampton, Ian Hood, Arup, John Preston, University of Southampton
This paper considers how to make the best use of available conventional and additional high-speed rail capacity, including the prioritisation of trains and the planning of interchange between conventional and high-speed routes.
The introduction and expansion of high-speed rail networks has been a major feature of transport developments over the past 50 years, reducing domestic and international travel times, encouraging modal shift from air transport, in particular, and, in some cases, facilitating economic regeneration. Britain is connected to the European high-speed railway network via the Channel Tunnel and the ‘High Speed 1’ (HS1) rail link between London and the Tunnel, and plans are in place for the construction of ‘High Speed 2’ (HS2), connecting the Midlands and the North of England to London and thus to the European network.
In addition to journey time reductions and modal shift from more environmentally damaging forms of transport, high-speed rail on dedicated infrastructure provides a significant direct increase in total passenger transport capacity, and, by replacing at least some inter-city rail passenger services on conventional routes, releases capacity on those routes, thus indirectly providing additional capacity for conventional freight and other passenger trains, including commuter and regional services.
A critical element of the planning and design of high-speed rail services is the location and spacing of stations, with a view to maximising the number of potential passengers served, while not including so many stations that end-to-end journey time savings are lost or unacceptably reduced. In this respect, the situation in Britain, and in England in particular, differs considerably from that in France, for example: while France’s large urban centres are typically separated by long distances through sparsely-populated rural areas, the major cities of England are more closely spaced, and the intermediate areas are typically more heavily populated.
The planning of locations for interchange between high-speed and conventional train services is another, related challenge, particularly in the context of an existing, relatively dense, conventional railway network. This aspect of the planning process includes consideration of the options for enabling high-speed services to run beyond the high-speed network to serve locations on the conventional network, as happens with high-speed domestic services on High Speed 1, and on some domestic and international TGV services.
By removing at least some higher-speed passenger services from parallel conventional routes, high-speed rail, in addition to directly releasing capacity on these routes, can deliver a reduction in the speed differentials between the remaining passenger and freight services that continue to use them, thus providing further additional capacity within constant capacity utilisation limits. The planning and prioritisation of the residual and additional services needs careful consideration, in order to achieve an advantageous balance between the remaining conventional services while maximising the potential additional capacity.
This paper describes work undertaken by Arup and others on the planning and development of high-speed rail in Britain, and to achieve the appropriate relationship between high-speed and residual conventional services on both HS1 and HS2. It also describes the challenges involved in the prioritisation of freight and passenger services with different performance and economic characteristics, and proposed methods and further research to address them and to optimise the prioritisation process and make the best possible use of the available capacity on both conventional and high-speed routes.
Association for European Transport