Roadway System Research Articles

Study on Multi-Parameter Variation of Smoke Flow in Inclined Roadway Fire

ABSTRACT Based on the fluid similarity theory, a “Mine inclined roadway fire simulation experimental system” with similarity ratio of 1:20 is established. The temperature, velocity, density and dynamic pressure of fire smoke under different inlet wind speed (0.5 m/s, 1.0 m/s, 1.5 m/s) were tested and analyzed, and the distribution of temperature, velocity, density and dynamic pressure of inclined roadway during fire was simulated and analyzed by Ansys numerical simulation software. The research shows that: The higher the inlet wind speed, the faster the heat diffusion and the temperature field tends to be flat and long, the wind speed changes in advance and the change is drastic, the gas density decreases, the dynamic pressure first decreases and then increases and then tends to stabilize, but the change trend of temperature, wind speed, gas density and pressure in the overall combustion process remains unchanged. The numerical analysis results are in good agreement with the experimental results. By studying the change law of smoke temperature, velocity, density and dynamic pressure of coal mine inclined roadway fire, the theory of coal mine roadway fire is further perfected, and the level of coal mine fire prevention and rescue is improved.

A Python toolkit for integrating geographic information system into regulatory dispersion models for refined pollution modeling

AERMOD is designated as U.S. Environmental Protection Agency (EPA)'s preferred air dispersion model for refined transportation project hot-spot analyses beginning in 2020. One of the key challenges in its modeling process is spatially encoding roadway geometry, especially when simulating highways with complex geometric designs. This research proposed an open-source Python package, GTA, which enables conversion of publicly available roadway Geographic Information System (GIS) layers into defined sources, and source-based emission rates from MOtor Vehicle Emissions Simulator (MOVES) output for AERMOD modeling. The research selected a suburban area in Atlanta, and conducted a comprehensive analysis in terms of annual PM2.5 concentration results and the speed of preparing AERMOD input files for highway network modeling both manually and using software developed based on the proposed methodology. The results prove that the proposed methodology significantly expedites the AERMOD input preparation process, and facilitates convenient testing of multiple modeling configurations for multi-scenario or sensitivity analysis.

Review of Risk Assessment Methods for Cybersecurity Attacks on Road Network and Intelligent Transportation System Applications

One of the most discussed infrastructure issues of our time is cybersecurity. A transportation system that connects not only people but also logistics to make the community around the world closer is one of the critical infrastructures requiring cybersecurity to perform its functions. Transportation systems include aviation, maritime, pipeline, railroad, and road networks. This study focuses only on the roadway network system. Cutting-edge technologies related to highway networks, such as variable message signs, vehicular ad hoc networks, and in-vehicle networks, have been developed to improve safety and efficiency. Those technologies make transportation systems more complex and integrated, bringing many potential vulnerabilities and cyber risks. This can attract an adversary to attack and exploit the system. The number of cybersecurity attacks on transportation systems has been growing for many years. However, it is not feasible to protect against all cybersecurity attacks in the system. The risk assessment concept is proposed to prioritize risk resulting from attacks to support decision-makers in formulating appropriate policies or countermeasures. This study reviews risk assessment methods for cybersecurity attacks on road networks and intelligent transportation system applications. Three potential risk assessment methods are examined for road network systems: the National Institute of Standards and Technology Special Publication 800-30, Attack Potential and Damage Potential, and the fuzzy analytic hierarchy process.

Urban Roadway in America: The Amount, Extent, and Value

Problem, research strategy, and findings We predicted the amount, share, and value of land dedicated to roadways within and across 316 U.S. primary metropolitan statistical areas. Despite the amount and value of land dedicated to roadways, our study provides the first such estimate across a broad range of metropolitan areas. Our basic approach was to estimate roadway widths using a 10% sample of widths provided by the Highway Performance Monitoring System and apply our estimates to the rest of the roadway system. Multiplying estimated widths by segment length and netting out double counting at intersections provided estimates of land area. We also matched roadway segments and areas to existing land value estimates and satellite-based measures of urbanized land. We found that a little less than a quarter of urbanized land—roughly the size of West Virginia—was dedicated to roadway. This land was worth around $4.1 trillion in 2016 and had an annualized value that was higher than the total variable costs of the trucking sector and the total annual federal, state, and local expenditures on roadways. Conducting a back-of-the-envelope cost–benefit analysis, we found that the country likely has too much land dedicated to urban roads. Takeaway for practice Federal, state, and local agencies dedicate substantial time, money, and resources to providing roadways. Even with relatively generous assumptions and no external costs from driving, however, we estimated that the average cost of expanding roadways exceeded the benefits by a factor of nearly three when accounting for land value. Policymakers should question policies focused on roadway expansion and consider options to reduce the amount of space dedicated to roadway in favor of more housing, offices, and other land uses. In addition to our findings, we provide a novel data set that academics and policymakers can use to draw their own conclusions about the state of America’s urban roadways.

On CO2 efficiency and trade-offs between sustainability, safety, economy and resilience in infrastructure developments

The escalating crisis of climate change underscores the pressing need to reduce global CO2e emissions substantially. At the same time, a major increase is expected in global demand for infrastructure systems. In meeting this challenge, we here provide and illustrate a novel modeling framework that affords decision support in pursuit of sustainable developments of infrastructure systems. Based on this framework, for the case of roadway traffic infrastructure systems, it is shown that different strategies for the development of roadway traffic infrastructure systems, yielding approximately the same economic benefits to society, can differ in their embedded carbon footprint by up to a factor of three. This knowledge has the potential to contribute significantly to sustainable developments in general and mitigation of climate change in particular. Our models and results may readily assist decision-makers in the construction industry, at national and supra-national scales, in identifying optimal strategies for infrastructure developments. Furthermore, our work may straightforwardly support regulatory bodies and code writers in defining requirements for material and structural performances for the next generation of standards and codes.

Stability Evaluation of Lanedada Twin Tunnel in KTFT

The construction of underground tunnels, particularly in roadway systems, is a highly complicated and demanding process, necessitating careful consideration of geological variability, environmental impact, and safety concerns. This thesis emphasizes the critical importance of determining the optimal separation between twin tunnels, balancing the need for environmental conservation, economic efficiency, and structural stability. The study particularly focuses on the Kathmandu Terai/Madhesh Fasttrack (KTFT), a major expressway project in Nepal, which includes twin tunnels at three different sites under varying geological conditions. A detailed case study is conducted on the Lanedada Twin Tunnel, spanning 1.430 kilometers through the Siwalik Hill. Various methodologies, including empirical, analytical, and numerical approaches, are employed to assess tunnel stability. The findings reveal discrepancies in predictions of tunnel squeezing, with Singh et al.'s method indicating no squeezing potential, while Goel et al.'s method identifies squeezing in half of the evaluated sections. Additionally, the approaches by Hoek and Marino (2000) and Shrestha and Panthi (2015) are applied to estimate tunnel deformation at six specific locations. An analysis of rock support systems using the Rock Massm Rating (RMR) classification and the Q system is presented. Special attention is given to the section at 34+160, where the RS2 software is utilized to simulate varying pillar widths between the twin tunnels, allowing for a comparative analysis of different scenarios. This research aims to contribute to the understanding and implementation of safer, more feasible twin tunnel constructions, thereby enhancing the effectiveness of large-scale infrastructure projects.

Flexible Permeable-Pavement System Sustainability: A Methodology for Stormwater Management Based on PM Granulometry

Permeable-pavement design methodologies can improve the hydrologic and therefore the environmental benefits of rural and urban roadway systems. By contrast, conventional impervious pavements perturb the hydrologic cycle, altering the relationship between the rainfall loading and runoff response. Impervious pavements create a hydraulically conductive interface for the transport of traffic-generated chemicals and particulate matter (PM), deleteriously impacting their proximate environments. Permeable-pavement systems are countermeasures to mitigate hydrologic, chemical, and PM impacts. However, permeable pavements are not always equally implementable due to costs, PM loadings, and design constraints. A potential solution to facilitate environmental benefits while meeting the traffic load capacity is the combination of two filtration systems placed at the pavement shoulders and/or pedestrian sidewalks: a bituminous-pavement open-graded friction course (BPFC) and an aggregate-filled infiltration trench. This solution is presented in this manuscript together with the methodological framework and the first results of the investigations into designing and validating such a combined system. The research was conducted at the laboratories of the Polytechnic University of Bari and the University of Florida, while an operational and full-scale physical model was constructed in Bari, Italy. The first results presented characterize the PM deposition on public roads based on granulometry (particle size distributions (PSDs) and particle number densities (PNDs)). Samples (n = 16) were collected and analyzed at eight different sites with different land uses, traffic, and pavements from different cities (Bari and Taranto, Italy). The PM analysis showed similar distributions (PSDs and PNDs), except for two samples. The gravimetric-based PSDs of the PM had granulometric distributions in the sand-size range. In contrast, the PNDs, modeled by a Power Law Model (PLM) (R2 ≥ 0.92), illustrated an exponentially increasing number of particles in the fine silt and clay-size range, representing less than 10% of the PSD mass. Moreover, the results indicate that PM sourced from permeable-pavement systems has differing impacts on the pavement service life.

The role of information dissemination in sustaining a stable and Resilient Traffic Network under disruption

ABSTRACT A functioning roadway system is key to any society and economy. Traffic events such as maintenance and accidents reduce roadway capacity and can have immediate, large and lasting impact on traffic conditions. This paper investigates the role of information dissemination as a control tool for reducing the negative effects of a traffic event. It examines how timely information can prevent unnecessary route changes and counteract misinformation, restoring traffic equilibrium faster. Systems that recover equilibrium more rapidly are considered more resilient. A traffic flow evolution model is applied to analyze network behavior post-disruption, with a model parameter interpreted as an information dissemination penetration rate adjustable by operators. Numerical experiments investigate the effects of the penetration rate on travel times, revealing a critical rate for quickly re-establishing a new equilibrium. Beyond this rate, greater traffic oscillations can be expected. The study determines the best information penetration rate to maximize network resilience while ensuring stability.

Road Damage Assessment

In this research, the emphasis is placed on the vital function of roadway systems in spurring economic growth, connecting different communities, and ensuring access to crucial services like education and healthcare. The study identifies several key factors contributing to the wear and tear of road infrastructures, such as extreme weather conditions, high traffic volumes, suboptimal construction techniques, and lack of regular upkeep. Specifically, the occurrence of potholes is highlighted as a major concern, leading to not only discomfort for commuters but also potential vehicle damage and increased risk of traffic incidents. To address this, the research proposes a novel approach that involves monitoring the flow and categorizing vehicles by their weight to gauge their impact on road surfaces. For the accurate identification and mapping of potholes, the study utilizes the advanced capabilities of the YoloV8 algorithm. This technique is further enhanced by integrating it with a mobile application and Google Maps, enabling a comprehensive and city-wide application of the pothole detection system. Roads are a critical component of a nation's infrastructure, but they are subject to deterioration over the time due to various factors. Road damage assessment software has emerged as an innovative solution to monitor, evaluate, and prioritize road maintenance needs. This report provides a comprehensive overview of road damage assessment software, starting with an introduction, followed by a literature survey, limitations of the existing systems, problem statement, proposed system, framework, design details, methodology, experimental setup, details of the database, performance evaluation, software and hardware setup, future work, and references. Key Words: Road , Potholes , Damage , deep learning, Accidents, YOLOv8

Management of road bridge networks in Italy by means of integrated SHM systems

Management of stocks with large number of bridges is a relevant issue for the Italian roadway system. In the last years the use of integrated SHM (Structural Health Monitoring) systems is being introduced within the framework of the modern BMS (Bridge Management Systems) with the aim of implementing a continuous damage identification strategy. In this framework, ambient vibration-based SHM has received most attention owing to its minimal intrusiveness, non-destructive character and global damage identification capabilities. A lot of research effort has been devoted in the last years to SHM techniques but ease of use, interpretability and minimal intervention of expert judgement are essential issues for the fruitful application of SHM in real and wide bridge networks. ANAS S.p.A., the main road managing Authority in Italy, is implementing a huge monitoring program on its bridge network with the main purpose of addressing the recent indications of the Italian guidelines for assessing and monitoring of bridges, and the University of Padova, together with the University of Perugia, Politecnico of Milan, University of Pisa and the other Universities of FABRE Consortium are supporting ANAS for the real application of modern SHM techniques. According to these actual needs, a new software suite called P3P has been developed and is being applied to a huge stock of bridges distributed in all the Italian territory.

Seismic fragility of circular piers in simply supported RC bridges: A proposal for capacity assessment

Bridges are crucial structures of a roadway system, always exposed to both natural and anthropic hazards. Several approaches have been investigated in the past two decades to evaluate the seismic vulnerability of bridges; the development of fragility curves represents a sound tool to evaluate their performances at a large scale. This study aims at the estimation of seismic fragility curves for a structural element of a very common bridge typology in Italy, that is the single circular cross-section pier of a simply supported Reinforced Concrete (RC) bridge. Two analytical methodologies for deriving fragility curves are applied to a case study model. The first one is the Capacity Spectrum Method (CSM). This method accounts for the non-linearities and the seismic energy dissipation, in fact it is based on a non-linear static analysis and the definition of Damage States (DSs) on the capacity curve of the piers. By contrast, the second one is the Response Spectrum Analysis (RSA), that is a methodology based on a linear method. By using both methods, a parametric study is carried out, varying the bridge’s geometrical and mechanical properties within standard ranges, to evaluate their effect on the seismic vulnerability of the pier. This study refers to four DSs and proposes a multilinear regression model to directly evaluate the pier’s seismic performances based on the geometrical and mechanical properties of the bridge to which it belongs.

Deformation processes in roadway support systems at deep shaft in Skalisty Mine

Deformation processes in roadway support systems at deep shaft in Skalisty Mine

Approach for Evaluating the Effectiveness of the Airport Roadway Traffic Sign System

The airport road traffic sign system is essential for drivers to find their destinations. However, no comprehensive design standards have been established for airport roadway traffic signs in China. An airport roadway traffic sign system was designed based on the Chinese Road Traffic Signs and Markings standard (GB5768-2009), called scheme 1. A second sign system was established using international standards and following drivers’ recognition, sign information hierarchy, called scheme 2. The Airport Roadway Traffic Sign System Evaluation Method (ARTSSEM) was established to evaluate the effectiveness of the airport roadway traffic sign system. This method includes a goal layer, a method layer, an indicator layer, and a comprehensive evaluation layer. We obtained drivers’ driving behavior data from the driving simulation. The subjects drove at a lower and more stable average speed in scheme 2 (63.71 ± 3.91) than in scheme 1 (65.89 ± 4.81). An ergonomic model that considers the sign system’s information demand, information comprehension, and information volume (DCI) was established and evaluated using subjective experiments. Scheme 2 provided a higher DCI score (0.46) than scheme 1 (0.17). The performance of the sign systems was comprehensively evaluated using the fuzzy evaluation method to evaluate the driving behavior, wayfinding performance, and ergonomics of the sign system. Scheme 2 (76.13) had a higher score than scheme 1 (74.13). The results revealed that scheme 2 performed better than scheme 1. The effectiveness of ARTSSEM was verified by the case study of the Daxing Airport signage system. This study provides a general approach to designing and evaluating other sign systems.

Study on Smoke Temperature Distribution Characteristics of Coal Mine Inclined Roadway Fire

ABSTRACT Mine roadway fire is a major natural disaster that threatens the safety of mine production for a long time. 65% of the total casualties of coal mines are caused by mine roadway fire. In order to study the smoke temperature distribution characteristics of inclined roadway fire in coal mine and reduce personnel injury and equipment loss. In this paper, the calculation formula of the maximum air flow temperature and the expression of the maximum temperature on the downwind side of the fire area are presented. Based on the actual roadway of Wusu Coal mine in Hohhot, Inner Mongolia, a “Mine inclined roadway fire simulation experimental system” with similarity ratio of 1:20 is established. The fire smoke temperature under different roadway inclination (5°, 10°, 15°) and different inlet wind speed (0.5 m/s, 1.0 m/s, 1.5 m/s) was tested and analyzed, and the temperature field of inclined roadway during fire was simulated and analyzed by Ansys numerical simulation software. The research shows that when the inlet wind speed is larger or the roadway inclination is larger, the heat diffusion is faster, the temperature field is longer and narrower, and the temperature is lower, but the temperature variation trend of the overall combustion process remains unchanged. By studying the temperature distribution of smoke in inclined roadway fire, it is convenient to take corresponding measures in time to minimize the impact of fire.

Research on a Speed Guidance Strategy for Mine Vehicles in Three-Fork Roadways Based on Vehicle–Road Coordination

Aiming at the traffic congestion problem of mining vehicles in the intersection area of three-fork roadways in coal mines, this paper proposes a speed guidance strategy based on a vehicle–road cooperative environment to adjust the running state of mining vehicles in the three-fork roadway system. The proposed speed guidance strategy can realize the safe and effective passage of underground mining vehicles to the greatest extent. Taking a three-fork roadway in a coal mine as an actual case, the operation of mining vehicles in the three-fork roadway is optimized and scheduled. Through the joint simulation of PTV VISSIM 4.3 traffic simulation software and PYTHON 3.7, the travel time, number of queuing vehicles, and delay time of mining vehicles passing through the three-fork roadway entrance under the two conditions of no speed and speed guidance in the coal mine are simulated and compared. The results show that after using the proposed speed guidance strategy for scheduling, mining vehicles can quickly pass through the three-fork roadway intersection. The travel time is reduced by 18.4%, the number of queuing vehicles is reduced by 41.5%, and the delay time is reduced by 24.1%, which effectively improves the transportation efficiency of underground mining vehicles.

Numerical simulation of the surface subsidence evolution caused by the flooding of the longwall goaf during excavation of thin coal seams

Underground mining has a significant influence on ground movement, which induces serious environmental disturbances on land. Movements of the rock strata can be the cause of changes in the hydrogeological regimes of groundwater. As a result, the risk of flooding of the longwalls goaf increases. The specific phenomenon of the Ukrainian Donbas is the flooding of the underground roadway system at the result of the closure of the mines. Water saturation of rocks leads to a decrease in its strength. The result is repeated subsidence. The activation of the ground movement processes over the longwall goaf due to their flooding has not been studied enough. In this paper, for the geological conditions of thin coal seams typical for the Ukrainian Donbas, ground movement evolution caused by flooding of longwalls goaf was studied. Ansys code was used to analyze the evolution of surface displacement in different hydrogeological conditions. As a result of numerical simulation, it was found that full flooding of the longwall goaf leads to an increase in surface subsidence by 22.4%, while the length of the trough increase by 1.3%. Maximal inclination increases by 34.4%, and maximal curvature – by 74%. This contributes to a significant increase in hazards for surface infrastructure located on the edges of the subsidence trough. The control of the negative impact on surface infrastructure objects, water and agro-industrial objects can be ensured by a timely prediction of ground movement and the implementation of surface controlling methods to prevent critical surface deformations.

A comprehensive dynamic continuous model of piezoelectric stack energy harvesters under arbitrary excitation considering electrodes and protective layers

Piezoelectric stack energy harvesters, by virtue of the higher mechanical-to-electrical energy conversion capability in the d 33 mode, have been used widely in various fields, such as railway system, roadway system, and human motion. Dynamic continuous models (DCMs) of piezoelectric stack energy harvesters can more accurately reflect the electromechanical behavior but are difficult to be established due to complex coupling between layers, particularly in the presence of arbitrary loads. The existing models often only considered harmonic excitations and often ignored electrodes and protective layers for simplicity. This paper proposed a comprehensive DCM of piezoelectric stack energy harvesters considering the electrodes and protective layers, which can be used to study the electromechanical performance of the energy harvester under both harmonic excitation and arbitrary excitation. Comparisons of the developed generic DCM with the analytical model based on piezoelasticity theory (a DCM which only considers the harmonic excitation) and the simplified model (a quasi-static continuous model which ignores inertia force of piezoelectric stack) are presented, with good agreements. Furthermore, the experiment results of two shapes of piezoelectric stacks, including tube and circular, are used to further confirm the reliability of the proposed model. In addition, effects of the electrode and protective layers on the dynamic properties are analyzed and discussed. The results show that the proposed DCM is effective and versatile to guide the design of piezoelectric stack energy harvesters subject to various types of loads.

Climate Change Impacts on North Carolina Roadway System in 2050: A Systemic Perspective on Risk Interactions and Failure Propagation

This research article presents a comprehensive assessment of the potential impacts of climate change on North Carolina's roadway system in 2050, considering six distinct scenarios, including sunny day and storm conditions, and three future climate projections. The study contributes to existing literature by incorporating risk interactions and failure propagation through a Travel Demand Modeling process. The analysis follows a three-step analytical approach, including identifying climate change scenarios, modeling climate stressors, and analyzing transportation system response. The results show potentially severe climate change threats, leading to 0.23 – 1.24% of trips underserved and 2.74 – 15.11% of roadway links on the southern coast operating at a speed of fewer than 10 mph. Moreover, the analysis reveals clear spatial patterns in climate change impacts, with the northern coast experiencing more inaccessibility and the southern coast facing greater congestion. The results show a non-linear and dynamic response of roadway system to climate change. The study highlights four policy implications, including increasing system redundancy, protecting critical infrastructure, acknowledging spatial disparities, and considering potential relocation strategies. The analysis also sheds lights on the mechanism behind roadway system response, showing the possible existence of a tipping point.

Paratransit service quality modeling reflecting users' perception-A case study in Dhaka, Bangladesh

Increasing usage of private cars and low service quality of public transport is an acute problem in many developing cities. The prerequisite is to meet the mobility needs, especially for low-income people, to ensure adequate capacity by the service provided. Paratransit is an indispensable mode of public transport, especially where the mass transit system is insufficient. Rapid increase in urban population, per capita income along existing transport infrastructure has stimulated their usage as a cheap and convenient public transport mode. Quality of service is considered as one of the most significant means to assess transit performance. To observe the performance of public transportation in roadway systems, overall passenger perceived service quality (SQ) has always been the most significant means of measurement. This research aims to establish a relationship between SQ variables describing the service of paratransit by Structural Equation Modeling (SEM) based on users' perceptions. An interview survey was conducted off-board to 2025 paratransit users at twenty paratransit routes in Dhaka metropolitan area (Bangladesh). Results show that the attribute of integration with supporting modes has the highest loading, inferring it as the most significant aspect of SQ. Attributes loading value may be explained according to the importance perceived by the users. Several SE models were developed using 21 service variables from 2000 questionnaires. Upon developing different models, the best model with three latent constructs was identified as the main characteristics for explaining the entire set of physical and service performance elements of the paratransit service. Three latent constructs were ‘Quality of transport’, ‘Transit performance’ and ‘Service quality’. Among 21 SQ variables, ‘Security of passenger’, ‘seat comfort level’, and ‘riding safety’ have been found to impart the greatest influence on the overall perceived SQ. The study findings support the data collected from paratransit users. This study may help the paratransit operators to determine variables that are decisive for SQ and their relation with the overall perceived SQ by the users. Understanding SQ variables, influencing passenger perception makes it easier to design and deliver good quality service.

Numerical Simulation of Subsidence Caused by Roadway System

Numerical Simulation of Subsidence Caused by Roadway System