Effects of increased traffic volume and speed heterogeneity on the capacity of a railway with dense mixed traffic

Abstract

Increasing demand for train travel implies a need for improved traffic. More frequent departures and new regional stops have to be coordinated with the desire to shorten travel times for passengers and on the same line be mixed with freight operations. This paper analyses how increased traffic predicted for 2020 affects the capacity of a 400-km section of the Southern Main Line in Sweden, a highly-utilised double-track line with heterogeneous and dense traffic with low punctuality, particularly as regards high-speed trains. In a second step, the consequences of raising the maximum speed for high-speed trains from 200 to 250 km/h are analysed. The purpose of the paper is to show the effects of these measures and discuss strategies for improving punctuality and increasing timetable flexibility based on the revealed weaknesses of the system by combining timetable analysis and simulation.The evaluation shows that an increase in traffic volume and speed differences leads to a decrease in the flexibility and reliability of the timetable. The punctuality of the high-speed trains becomes unacceptably low. The tested approaches to normalise the effects of increased traffic and speed on flexibility and punctuality are shown to be insufficient. Capacity utilisation on the line is so high that recovery is not possible.

Impact of block section length on the headway of mixed speed trains in high-speed railway

“…Literature [1] studied the impact of mixed operations on the carrying capacity of high-speed railways and concluded that trains with different speeds operating on the same signal display system would increase the train headway and reduce the line capacity. Literature [2][3][4] proposed that the increase in traffic volume and speed difference not only leads to a decrease in schedule flexibility and reliability but also makes the system sensitive to interruptions, with speed combinations having the most impact on high-density railway lines. Studies in the literature [5][6] show that when the speed difference between trains does not exceed 50 km/h and the proportion of low-speed trains running is about 90%, the impact on the line carrying capacity is minimal.…”

Optimized Train Dispatching and Rescheduling During a Disruption in a Bottleneck Section

“…Delays encountered in railway systems can be categorized as either primary or secondary delays. Warg et al [3] defines Primary delays as the types of delays affecting a particular train schedule and those delays are not as a result of malfunction of other trains using the line. Whereas secondary delays are defined as the delays caused by earlier delays of other trains within the network sharing the same infrastructures, passenger transfers, transfers and reallocation of crew and rolling stock connections among others.…”

Modeling the Dynamic Behavior of Track Transitions Along Shared Track Corridors

“…In Turkey, sharing High Speed Train (HST) infrastructure with both freight and passenger trains is advised; it is believed to be practical and economically efficient, especially for transporting small cargo and postal mail using HSTs (Ertem and Özcan, 2016). Warg (2012) indicated that there are requirements for increasing the maximum speed of HST and adding more new regional stops for flexibility in Sweden. Ramaraju (2013) stated that train speed and capacity are critical problems in India because of challenges associated with track sharing between passenger and freight trains.…”