Search Results (8)

This study examines the modernization of the 61-4179 TVZ passenger coach for transporting light automobiles up to 3 tons, addressing the efficiency of multifunctional rail use. The objective was to assess how additional mass–dimensional loading influences strength, load distribution, and the dynamic stability of the vehicle–track system. Finite element simulations in ANSYS Workbench 2021 R2 determined stress distribution, deformations, and safety margins, while multibody dynamics modeling in Universal Mechanism evaluated wheel–rail contact forces, carbody accelerations, and stability coefficients. Field tests on curves with radii of 350 m and 300 m at 60 km/h validated the models. Carbody accelerations were 0.65–0.68 m/s², below the 0.7 m/s² regulatory limit; wheelset attack angles remained under 0.01 rad; and derailment safety coefficients were 1.6–1.8, all meeting international standards. Uniform load distribution maintained stability and suppressed oscillations. However, critical scenarios (wheel wear, extreme flange clearance, higher speeds) produced parameters approaching threshold values. To mitigate risks, clearance adjustment per δ₀ standards, a 1:20 guard-rail inclination, and optimized crossing profiles are proposed. These measures reduced lateral dynamic forces by 12–15% and raised the strength coefficient by 1.2–1.3. The results confirm technical feasibility, operational safety, and extended service life, supporting sustainable multimodal transport development. Full article

Epidemiological analysis has revealed key insights into the frequency, severity, and circumstances surrounding subway-to-pedestrian incidents; however, there remains a lack of available impact test data specific to this impact type that can be used in modelling and countermeasure design studies. To address this gap, nine controlled impact tests were conducted using a cylindrical headform to derive force–penetration relationships for foam, as well as foam encased in 1 mm aluminium or 3 mm ABS shells. These relationships were validated in MADYMO multibody simulations. Building on a previous multibody computational study of subway-to-pedestrian collisions this research evaluates three passive countermeasure designs using a reduced simulation test matrix: three impact velocities (8, 10, and 12 m/s) and a trough depth of 0.75 m. In subway collisions, due to the essential rigidity of a subway front relative to a pedestrian, it is the pedestrian stiffness characteristics that primarily dictate the contact dynamics, as opposed to a combined effective stiffness. However, the introduction of energy-absorbing countermeasures alters this interaction. Results indicate that modular energy-absorbing panels attached to the train front significantly reduced the Head Injury Criterion (HIC) (by 90%) in the primary impact and pedestrian-to-wheel contact risk (by 58%), with greater effectiveness when a larger frontal area was covered. However, reducing primary impact severity alone did not substantially lower total fatal injury risk. A rail-guard design, used in combination with frontal panels, reduced secondary impact severity and led to the largest overall reduction in fatal injuries. This improvement came with an expected increase in hospitalisation-level outcomes, such as limb trauma, reflecting a shift from fatal to survivable injuries. These findings demonstrate that meaningful reductions in fatalities are achievable, even with just 0.5 m of available space on the train front. While further development is needed, this study supports the conclusion that subway-to-pedestrian fatalities are preventable. Full article

With global warming and the frequent occurrence of extreme weather, damage to urban rail transit systems and casualties caused by rainstorm disasters have increased significantly and are becoming more serious. This research developed a network model for the evolution of operational risk in URT systems under rainstorm scenarios that can cause 35 typical accidents. Furthermore, we also investigated the evolution mechanism and devised improvement strategies. Through the network, combined with the complex network theory, the study explored the critical risks and the extent of their impact on the network and proposed optimized strategies to avoid these critical risks. The results show that risk nodes such as R1, R4, R18, and R21 have the most significant impact on the evolution network, both in static and dynamic networks, indicating that station flooding, train stoppage, heavy rainfall, and ponding are the most critical risks to guard against. Gauging the evolution of operational risks in urban rail transit systems and adopting reasonable avoidance measures in this research can effectively improve resilience to rainstorm disasters and the level of operational safety, which can contribute to the sustainable development of transport infrastructure. Full article

To reduce the occurrence of accidents during the train-to-train collision test, it is necessary to carry out research on derailment protection. According to the characteristics of the train-to-train collision test, a method of using a U-steel as a guard rail is proposed. The protection range of the guard rail is obtained through the geometric relationship. The protection ability and damage risks of the guard rail in different impact conditions, impact velocities, and installation positions are studied. Additionally, the section shape is optimized for multiple objectives. The results show that the guard rail can effectively reduce the lateral displacement and the rotation angle of the bogie within the protective range and protect the vehicle, but for some conditions, the damage risk of the guard rail itself is greater. The maximum stress of the optimized structure is reduced by 28.19%, which reduces the risk of damage, and the optimized guard rail still has a good protection ability. Full article

Thailand has the second-highest rates of road traffic mortality globally. Detailed information on the combination of human, vehicle, and environmental risks giving rise to each incident is important for addressing risk factors holistically. This paper presents the result of forensic road traffic investigation reports in Thailand and determines risk factor patterns for road traffic injuries. Detailed forensic reports were extracted for 25 serious traffic accident events. The Haddon matrix was used to analyze risk factors in three phases stratified by four agents. The 25 events analyzed involved 407 victims and 47 vehicles. A total of 65.8% of victims were injured, including 14.5% who died. The majority (66.1%) of deaths occurred at the scene. Human-error-related factors included speeding and drowsiness. Passenger risks included not using the seat belt, sitting in the cargo area and the cab of pickups. Overloaded vehicles, unsafe car modifications, no occupant safety equipment and having unfixed seats were vehicular risks. Environmental risks included fixed objects on the roadside, no traffic lights, no guard rails, no traffic signs, and road accident black spots. At present, traffic accidents cause much avoidable severe injury and death. The outcome of this paper identifies a number of preventable risk factors for traffic injury, and importantly examines them in conjunction. Road traffic safety measures need to consider how human, vehicle, and environmental risks intersect to influence injury likelihood and severity. The Haddon matrix is useful in identifying these pre- and post-accident risk factors. Furthermore, the sustainable preventions of road traffic injury need to address these risks together with active law enforcement. Full article

Objective: This paper examines infrastructural and route environment correlates of cycling injury risk in Britain for commuters riding in the morning peak. Methods: The study uses a case-crossover design which controls for exposure. Control sites from modelled cyclist routes (matched on intersection status) were compared with sites where cyclists were injured. Conditional logistic regression for matched case–control groups was used to compare characteristics of control and injury sites. Results: High streets (defined by clustering of retail premises) raised injury odds by 32%. Main (Class A or primary) roads were riskier than other road types, with injury odds twice that for residential roads. Wider roads, and those with lower gradients increased injury odds. Guard railing raised injury odds by 18%, and petrol stations or car parks by 43%. Bus lanes raised injury odds by 84%. As in other studies, there was a ‘safety in numbers’ effect from more cyclists. Contrary to other analysis, including two recent studies in London, we did not find a protective effect from cycle infrastructure and the presence of painted cycle lanes raised injury odds by 54%. At intersections, both standard and mini roundabouts were associated with injury odds several times higher than other intersections. Presence of traffic signals, with or without an Advanced Stop Line (‘bike box’), had no impact on injury odds. For a cyclist on a main road, intersections with minor roads were riskier than intersections with other main roads. Conclusions: Typical cycling environments in Britain put cyclists at risk, and infrastructure must be improved, particularly on busy main roads, high streets, and bus routes. Full article

Up-to-date geodatasets on railway infrastructure are valuable resources for the field of transportation. This paper investigates three methods for mapping the center lines of railway tracks using heterogeneous sensor data: (i) conditional selection of satellite navigation (GNSS) data, (ii) a combination of inertial measurements (IMU data) and GNSS data in a Kalman filtering and smoothing framework and (iii) extraction of center lines from laser scanner data. Several combinations of the methods are compared with a focus on mapping in tree-covered areas. The center lines of the railway tracks are extracted by applying these methods to a test dataset collected by a road-rail vehicle. The guard rails in the test area were also extracted during the center line detection process. The combination of methods (i) and (ii) gave the best result for the track on which the measurement vehicle had moved, mapping almost 100% of the track. The combination of methods (ii) and (iii) and the combination of all three methods gave the best result for the other parallel tracks, mapping between 25% and 80%. The mean perpendicular distance of the mapped center lines from the reference data was 1.49 meters. Full article

In order to achieve the objectives of the Paris Climate Change Agreement, the conversion of our economy, which is still dominated by fossil carbon, to the bioeconomy model must be completed by 2050. This requires a shift from oil, gas and coal to agricultural, forestry and marine raw materials and will affect the global processing chains for energy, fuels and chemicals. However, the land required for the production of raw materials is competing with the production of food and animal feed. In addition, future land use must better take into account planetary boundaries and the preservation of ecosystem services. In order to achieve economic, ecological and societal sustainability, the necessary measures must therefore be geared towards the UN’s sustainability goals. Against this background, the future bioeconomy will have to concentrate on the food, chemical and heavy fuel sectors. Important sub-areas are alternative animal protein for nutrition, feedstock efficiency in the processing of bio-based raw materials, and the expansion of the raw materials spectrum. This requires enormous investment in industrial facilities, the integration of newly emerging value chains and the necessary infrastructure. The annual global investment requirements for renewable energy, bio-based chemicals and fuels, and ecosystem services is estimated at USD 1–2 trillion over the next three decades, equivalent to about 1.3–2.6% of global GDP. This article discusses the implications and guard rails of the bioeconomy model, as well as capital needs and possible sources. Full article