Road intersections play a key role in traffic management. Modern roundabouts require entering vehicles to yield to the circulating flow, and have proven highly effective in granting high performance levels to both new and redesigned intersections; therefore, their use has widely spread around the world over the years. The choice of the correct shape, size and signage of a roundabout is essential to accomplish the desired results in terms of performance and safety. In order to achieve these goals, designers have moved away from conventional layouts such as single-lane and multilane roundabouts, conceiving more and more unconventional solutions (spiral, turbo and two-geometry roundabouts). Alongside this design evolution, research has been conducted on functional analysis of roundabouts: several authors and authorities have developed capacity assessment models that are suitable for the analysis of unconventional roundabouts, but nowadays no complete review of such models is available. The aim of this paper is to collect descriptions of the main types of conventional and unconventional roundabouts, with a focus on their geometric features and applicable capacity assessment models.

Urban rapid transits are one of the most popular transportation methods these days. They are equipped with large-capacity air compressors because they use pneumatic pressure to supply power for braking, door opening and closing. Passengers tend to complain about vibration and noise generated during the operation of the air compressor. To address such issues, the excitation force generated in an air compressor mounted on a railway car was indirectly measured in this study. In order to accurately predict the excitation force transmitted to the mount rubber, the impedance matrix method technique was applied, which uses acceleration and the inverse of transfer functions. The proper locations of the measuring acceleration were also investigated. The calculated results of the transmitting force were then compared with the directly measured values.

The article uses numerical modelling to verify the impact of non-traffic load (water and frost) on sub- grade structure freezing of railway tracks with different routing (embankment and cut). The introduction characterizes two actual railway track models in the campus of the University of Žilina, named experimental stand DRETM – Department of Railway Engineering and Track Management (two measuring profiles were considered here: second measuring profile – embankment, third measuring profile – cut). The second part of the article brings the results of numerical modelling of non-traffic load impact on subgrade structure freezing in two respective profiles. Here, the course of the winter period 2016/2017 for Žilina and the climatic conditions of the winter period 2004/2005 measured for Poprad were applied (the values of the air frost index achieved in Poprad were approximately identical to or higher than the values in Žilina). The conclusion includes a comparison of the individual methods of rail track routing, a summary of achieved results of numerical modelling of subgrade structure freezing and sufficiency assessment of subgrade surface protection from the adverse effects of frost.

Taipei Main Station of Taipei Mass Rapid Transit is the busiest transport hub in Taiwan in terms of ridership. Its complex layout and high number of passengers frequently lead to congested transfer traffic patterns. This study examined passengers’ walking trajectories and behaviours and the relationship between crowding and train movement at the transfer concourse on floor B2 of Taipei Main Station to understand the factors of interference and congestion during traffic flow. An improvement plan was subsequently proposed. This study observed that because more passengers situated themselves in the middle cars than the front and rear cars, most boarding and alighting passengers used specific escalators to enter and exit the platform level. In addition, passengers’ walking flow tended to be affected by their personal moving distances, the movement of other passengers and traffic volume. Transfer passengers preferred to use escalators or stairs closer to them, resulting in poor traffic diversion inside the platform. In particular, congestion frequently occurred at the fork near the T junction, where most passenger interferences were recorded. Passengers tended to lean against walls or walk between pillars to mitigate the conflicting flow of movement among them. Other walking trajectory factors included the locations and directions of escalators, stairs and turnstiles. This study used Unity3D software to construct three traffic diversion proposals based on observation records. The proposals were used to simulate and verify improved traffic patterns and mitigate interference. The simulations revealed that moderate changes in the upward and downward directions of escalators could facilitate smoother transfer traffic patterns. Escalators with traversing directions that better adhere to passengers’ traffic patterns may substantially increase passengers’ walking speeds regardless of the direction they are coming from, thereby effectively mitigating congestion at the T junction.

The present work addresses traffic rescheduling in case of electric infrastructure failure. The power available for train traction is restricted and the traffic must be reorganized according to this constraint. The system behaviour is computed using a dynamic multi-physics railway simulator which gives physi- cal quantities such as the train speed profiles, voltage along the catenary lines and temperatures. The rescheduling problem relies on this non-linear model, with a large number of continuous and discrete variables, constraints on dynamic outputs (typically voltage limits) and a high computation cost. We propose a rescheduling process based on sensitivity analysis in order to analyse the behaviour of this complex system and obtain information about the adjustment operations needed in order to reschedule the traffic in an optimal way. Our approach is based on statistics, with predefined variation ranges of the input parameters. In a first stage, variance decomposition-based sensitivity analysis (generalized Sobol indexes) is used for prioritization and fixing factors; then regional sensitivity analysis is used for factor mapping. The proposed approach has been tested on a simple case, with a nominal traffic running on a single-track line. The considered incident is the loss of a feeding power substation. The variables to be adjusted are the time interval between departure times and speed reduction in the vicinity of the faulty substation. The results show that increasing the time interval between trains is the most influential vari- able. Pareto-optimal fronts are also built in order to perform multi-criteria analysis according to travel- ling time, train delays and traction energy.

The Virtual Balise concept has been demonstrated and shared among the ERTMS community as a mean to replace the physical balises by implementing a train Location Determination System (LDS) based on GNSS. It is evidenced both by the results of recent and current EC-supported R&D projects (e.g. 3InSat, ERSAT EAV, STARS, RHINOS, NGTC), the Sardinia Trial Site (Cagliari – San Gavino double track lines) equipped with a ERTMS Level 2 based system with Virtual Balises and the Ansaldo STS Freight SIL 4 ERTMS Level 2 system based on GPS L1 positioning system in commercial service in Australia.

In order to introduce the safe high-integrity LDS system into ERTMS/ ETCS and use it in railway operations in EU member states (MSs), it is necessary to develop and to authorize it according to relevant European and national regulations. It means that this LDS and its integration into ERTMS must pass through a certification and authorization process compliant with the applicable CENELEC standards and EU regulations.

This article deals with a possible certification process of a train LDS as a new subsystem of the ERTMS/ETCS interoperability constituents. Special attention is paid to a possible certification strategy in case of external GNSS safety-of-life service employment via an augmentation network. A possible certification framework for the whole LDS comprising on-board and trackside subsystems is outlined as well. Since the introduction of GNSS into ERTMS/ETCS represents a significant change within EU railway network, then the required common safety method must be applied. In this framework, a new pilot line has been launched by RFI with Ansaldo STS aiming to contribute to the identification of a possible certification process for deploying an ERTMS Level 2, baseline 3 with GNSS localization and public telecom solutions by 2020.

Recently safety of Korean railway lines has been threatened by typhoon and heavy rainfall due to global warming and representative rainfall induced risks are landslides, slope failure, debris flow, fallen rocks etc. Risks of slope failures are evaluated by deformation of ground surface and underground movements. But many bore holes and sensors must be equipped in the ground for detecting of deformation of ground movements. Furthermore, it is not easy to confirm slope failure immediately and needs much time for post-processing of various data. Only one or very specific sections could be monitored for limited area due to budget. A multipurpose sensor is developed for overcoming these problems by use of data from inclinometer installed on the ground surface. Motions at a point of ground surface could be simply divided into rotation and linear movements and they might be representative sensor signals. In this study, failure types, slip surface, failed mass and failure direction could be recognized by use of these characteristics; sensor data and an algorithm to detect these movements are suggested. Failure shapes such as circular and planar failure are estimated by combination of simplified ground movements. For determination of a two-dimensional (2D) slip surface, 3D coordinates of a main slope profile and all sensor locations should be defined. Then specific equation to estimate slip surface is selected. After selection of starting and ending point of slip surface, the tangent value of a slip surface could be calculated from each sensor. 2D slip surface is calculated by combination of sensor location, the equation, tangent values and each ending point. 3D failed soil mass is also estimated from various 2D slip surfaces. By use of centre of mass, we could get movement direction of failed soil mass. An examination of this algorithm has been executed in a railway slope. Consequently, it is possible to estimate slip surface and failed soil mass using data from ground surface.