Work Zone Research Articles

Automated detection of dangerous work zone for crawler crane guided by UAV images via Swin Transformer

Crawler crane overturning often results in many casualties and property damage. However, the existing research on overturning prevention mainly focuses on the internal factors of crawler cranes while ignoring the environmental factors represented by the subgrade bearing capacity. On this basis, this work summarizes three types of dangerous work zones including dangerous work zone with pit, dangerous work zone with unhardened area, and dangerous work zone with water with poor subgrade bearing capacity and develops an automated method for detection. A Mask Transformer model is adopted by using Swin Transformer as backbone network to recognize and segment the images obtained from an unmanned aerial vehicle. The detected images are transformed into a safety risk map that provides the driver with risk information about the dangerous work zone. Results show that the model proposed, which has been applied in a real engineering project, achieves a good detection effect.

Study on the Median Opening Length of a Freeway Work Zone Based on a Naturalistic Driving Experiment

Median openings are an effective traffic organization mode for freeway crossover work zones, and their length is one of the most important control indicators to ensure traffic safety in work zones. In this paper, a theoretical calculation model of the median opening length was established according to the lane-changing demands of vehicles crossing through the median opening of the freeway. Based on the calculation model, the influencing factors of the median opening length were analyzed, and the calculation values of the median opening length under different speed limits, median widths and cross slopes were proposed. A naturalistic driving experiment of drivers’ safety and comfort, with 48 participants at four opening lengths of 40, 70, 100 and 130 m in a typical freeway work zone, was carried out based on the calculated length values and the driving workload, expressing drivers’ safety and comfort. It was found that the median opening length of the freeway had a positive correlation with the vehicles’ running speed and the drivers’ driving workload: the shorter length reduced the running speed of the vehicles and led to uncoordinated running speeds in the work zone; the longer length caused driver tension and led to the vehicles’ running speed and speed variability being too high. The research results indicated that the median opening length of freeway work zones is an important factor affecting the vehicle running speed, driving workload and speed limit compliance rate.

Validation of a Sporicidal Bio-Decontamination Process for use in Pharmaceutical Isolators in an NHS Aseptic Manufacturing Unit

The recently published revision of EU GMP Annex 1 Manufacture of Sterile Medicinal Products includes a requirement for pharmaceutical isolators to undergo a bio-decontamination process of the interior which should be automated, validated and controlled within defined cycle parameters and include a sporicidal agent. It is widely accepted that the easiest way to achieve this is by converting Hydrogen Peroxide (H2O2) liquid into a state that will diffuse readily through the closed isolator chamber leading to bio-decontamination of all surfaces which it comes into contact with. The technology to do this has been around for years and can be validated to give a high level of assurance of surface bio-decontamination comparable with sterilization when used on surfaces in the isolator critical work zone. This type of activity is routinely used in large-scale sterile manufacturing that takes place in the pharmaceutical industry where the amount of materials and timescales involved make this viable. In the NHS, aseptic preparation and manufacture of sterile products is carried out in isolators both for immediate use and for stock in anticipation of demand. Automated bio-decontamination systems are available but their use is much less than in the pharmaceutical industry and reliance is still placed on manual spraying and wiping of surfaces with disinfectant agents such as alcohol and hydrogen peroxide. This brings a degree of variability and is more difficult to validate. For sterile manufacturing units holding an MHRA Specials Manufacturing licence the expectation is that proper consideration is given to using an automated bio-decontamination process or there is justification for not doing it. For units preparing products for immediate use there is not the same expectation but as standards are improved, it is reasonable to assume it may become the case in the future. To use this type of process requires it to be integrated into the isolator, meaning either buying a new isolator or retrofitting to an existing one. The relatively high cost of this is a barrier to pharmacy department aseptic units using the technology. There is a range of bio-decontamination systems on the market from Devea (www.devea environnement.com)which are claimed to be suitable for use in hospital pharmacy clean room facilities. One model from this range, the Phileas Genius is a simple, stand-alone battery powered unit that generates vapourized hydrogen peroxide of particle size 5-10 µm from 7.4% solution using novel spinning disc technology. This generator can be transferred into and out of any closed isolator work zone through the transfer hatch (as long as the hatch door is wide enough) and can be used to do pre-programmed cycles (called zones) to routinely decontaminate inner surfaces.

Combining emerging hotspots analysis with XGBoost for modeling pedestrian injuries in pedestrian-vehicle crashes: a case study of North Carolina

Pedestrians might face more dangers and sustain severer injuries in crashes than others. Also, the crash data has inherent patterns related to both space and time. Crashes that happened in locations with highly aggregated uptrend patterns should be worth exploring to examine the most recently deteriorative factors affecting pedestrian-injury severities in crashes. Therefore, applying proper modeling approaches is needed to identify the causes of pedestrian-vehicle crashes to improve pedestrian safety. In this study, an emerging hotspot analysis is firstly utilized to identify the most targeted hotspots, followed by a proposed XGBoost model that analyzes the most recently deteriorative factors affecting pedestrian injury severities. The overall accuracy of the best model on the hotspot dataset is 94.49%, which shows a relatively high performance compared to conventional models. Seven factors are identified to increase the likelihood of fatal injury, including “land development: farm, wood and pasture” (FWP), “interstate”, “US route”, “hit and run”, “alcohol-impaired driver” (AID), “urban”, and “alcohol-impaired-pedestrian”. While for incapacitating injury, there are five significant factors including “work zone”, “interstate”, “US route”, “curved roadway” and “alcohol-impaired-pedestrian”. The results of this research could give a solid reference for the identification of contributing factors affecting pedestrian-injury severities to policymakers and researchers.

Simulation Study of Passing Drivers’ Responses to the Autonomous Truck-Mounted Attenuator System in Road Maintenance

The autonomous truck-mounted attenuator (ATMA) system is a lead–follower vehicle system based on autonomous driving and connected vehicle technologies. The lead truck performs maintenance tasks on the road, and the unmanned follower truck alerts passing vehicles about the moving work zone and protects workers and the equipment. While the ATMA has been under testing by transportation maintenance and operations agencies recently, a simulator-based testing capability is a supplement, especially if human subjects are involved. This paper aims to discover how passing drivers perceive, understand, and react to the ATMA system in road maintenance. With the driving simulator developed for this ATMA study, the paper performed a simulation study wherein a screen-based eye tracker collected 16 subjects’ gaze points and pupil diameters. Data analysis evidenced the change in subjects’ visual attention patterns while passing the ATMA. On average, the ATMA starts to attract subjects’ attention from 500 ft behind the follower truck. Most (87.50%) understood the follower truck’s protection purpose, and many (60%) reasoned the association between the two trucks. Nevertheless, nearly half of the participants (43.75%) did not recognize that the ATMA is a connected autonomous vehicle system. While all subjects safely changed lanes and attempted to pass the slow-moving ATMA, their inadequate understanding of the ATMA is a potential risk, for issues such as cutting into the ATMA. The results implied that transportation maintenance and operations agencies should consider this in establishing the deployment guidance.

Quantifying Operational Impacts of Variations in Work Zone Setups, Traffic Demand, and Traffic Composition: A Case Study

The presence of work zones due to pavement repair and rehabilitation is very common in highway facilities. Lane closures associated with work zones result in capacity reduction, which, in turn, often leads to increased congestion at such locations. This paper documents findings from a study that investigated the performance of freeway facilities in the presence of work zones under various Temporary Traffic Control (TTC) and lane closure scenarios while taking under consideration traffic composition and driving behaviors. The study site was an approximately 10-mile freeway segment of Interstate 65 (I-65) located in Birmingham, AL. The testbed was coded in PTV VISSIM, a microscopic simulation analysis platform, for: 1) baseline conditions (i.e., no work zone presence) and 2) work zone conditions with single lane closure (i.e., 3-to-2 lane closure). Work zone scenarios were coded for two TTC strategies, namely, early merge and late merge control and for three different positions of the lane closure (i.e., left, right, and center lane closures). The length of the work zones varied from 1000 to 2000, and 3000 ft. Sensitivity analysis was performed to document the operational impacts of varying heavy vehicle percentages, changes in drivers’ aggressiveness, and projected traffic demand changes. The impacts were quantified using linked-based measures of effectiveness (MOEs) such as travel time, and travel time index. The study results show that there is no significant change in travel time index due to the variation of work zone length across the study corridor. Under similar traffic control and demand conditions, a center lane closure consistently results in significantly higher travel time index than a left or right lane closure and should be avoided. Consideration of operational impacts of changes in truck percentage indicates that the corridor can absorb an increase in truck percentage from 10% to 15%, while performance rapidly deteriorates when a higher percentage of trucks is present in the traffic stream. The study findings can be used to guide transportation agencies in their future efforts to develop strategic lane closure plans that minimize congestion.

Driver behavior on road work zones: a systematic review

The driver behaviour is a major concern on work zones, being the cause of a high number of drivers and workers’ deaths. In this paper, a systematic review was conducted, according to the Prisma protocol, focusing on driver behavior studies on work zones. The review involved summarizing and categorizing the many factors that can influence the behavior of the drivers. Based on the literature, it was possible to identify that driver behavior in a work zone has several correlated factors. Although the driver is the centerpiece, he/she cannot be treated individually. His/her reaction to the forces he/she perceives, including the other drivers, can vary depending on stimulants around him/her. Therefore, future studies must take into account these factors in order to achieve a better understanding of driver behavior on Road Work Zones.

Improving Safety in the Maintenance of Infrastructures: Design of a UAV-Based System for Work zone Monitoring

Considering the crucial role in the economy of road infrastructure, their maintenance is of the utmost importance. Robotization and automation of maintenance works can help to promote the efficiency and sustainability of the transportation network. At the same time, work zones foresee an increased risk of accidents and injuries. In this context, work zone traffic monitoring during maintenance can help to reduce the number of accidents and injuries. This manuscript describes the high-level design of an optical system using artificial intelligence and based on the operation of remotely piloted systems to enhance the segmentation and signaling of work areas to minimize risks both for road users and maintenance workers in the presence of automated robotic solutions. The future trends and steps in the project will include the low-level design and the implementation of the system.

Impact of Construction Work Zone on Urban Traffic Environment

Abstract Objectives Traffic management is challenging during construction because of the effects of traffic congestion, travel time, delay, and queue length. Long-term work zones on urban roads lead to many problems such as speed, inconvenience, and economic losses to drivers, which are focused on in previous studies. Methods Moreover, due to the construction work zone (CWZ), the impact on environmental factors such as air quality and noise levels was not focused on. Because of the building work zones, this research focused on comprehending how traffic congestion measurements and environmental factors affect urban traffic management. Findings The present research uses TransCAD to estimate air pollution due to increased traffic in the urban areas. Furthermore, three nonlinear AI-based models (ANFIS, FFNN, and SVR) and one linear black box model were developed to predict the noise level in the city, in which each contained the total traffic and speed as well as the ratio of heavy vehicles in the traffic. Novelty For traffic control, a variety of techniques are available, including video data analysis, infrared sensors, inductive loop detection, wireless sensor networks, etc. These are all practical techniques for efficient traffic management. It is necessary to conduct studies on the amount of traffic, the topography, accidents, time delays, and the level of safety offered in the work area. Construction operations are facilitated by the implementation of traffic flow, and during this process, long-term CWZs are inevitable. Therefore, the proposed model accomplishes the goal, namely that only analytical research and a few traffic diverter signs point drivers to alternate routes to their destinations.

Accounting for Heterogeneity in Stop Frequency Models of Work Tours Using Latent Class Poisson Models

Stop frequency models, as one of the elements of activity based models, represent an important part of travel behavior. Unobserved heterogeneity across the travelers should be taken into consideration to prevent biasedness and inconsistency in the estimated parameters in the stop frequency models. Additionally, previous studies on the stop frequency have mostly been done in larger metropolitan areas and less attention has been paid to the areas with less population. This study addresses these gaps by using 2012 travel data from a medium sized U.S. urban area using the work tour for the case study. Stop in the work tour were classified into three groups of outbound leg, work based subtour, and inbound leg of the commutes. Latent Class Poisson Regression Models were used to analyze the data. The results indicate the presence of heterogeneity across the commuters. Using latent class models significantly improves the predictive power of the models compared to regular one class Poisson regression models. In contrast to one class Poisson models, gender becomes insignificant in predicting the number of tours when unobserved heterogeneity is accounted for. The commuters are associated with increased stops on their work based subtour when the employment density of service-related occupations increases in their work zone, but employment density of retail employment does not significantly contribute to the stop making likelihood of the commuters. Additionally, an increase in the number of work tours was associated with fewer stops on the inbound leg of the commute. The results of this study suggest the consideration of unobserved heterogeneity in the stop frequency models and help transportation agencies and policy makers make better inferences from such models.

Traffic Flow Characteristics in Work Zone and Non-Work Zone Environment and Its Impact on Road Crashes at the Segment Level

Traffic Flow Characteristics in Work Zone and Non-Work Zone Environment and Its Impact on Road Crashes at the Segment Level

A Morphometric Study of Cadavers for the Anterior Approach to the Lower Lumbar Spine.

To explore the relationship between the retroperitoneal vasculature and anterior surface of the lower spine, and to establish values for aiding in prediction of the pertinence of anterior approach at the L4-L5 and L5-S1 intervertebral discs. The study included 13 fresh human cadavers. After exploration of the abdominal cavity and removal of the visceral organs, the vasculature, and anterior spinal surface were revealed beneath the lower extension of the perirenal fascia. Morphometric measurements of the great vessels and the intervertebral discs were obtained. All measurements were analyzed and presented as mean and standard deviation. Differences in the values between sexes were assessed. The anterior height of the L4-L5 and L5-S1 intervertebral disc was 6.8 ± 0.81 mm and 6.7 ± 0.99 mm, respectively. The widths of the aorta, inferior vena cava, right and left common iliac arteries, and right, and left common iliac veins were 16.4 ± 3.58, 20.6 ± 3.36, 11.5 ± 2.32, 11.5 ± 2.43, 14.7 ± 3.13, and 15.5 ± 3.27 mm, respectively. The mean aortic bifurcation angle was 45.5°. The aortic bifurcation was located above the lower endplate of the L4 vertebrae in 53.8% of the cadavers. The area of the interarterial and interiliac trigones was 14.6 ± 5.33 cm < sup > 2 < /sup > and 7.1 ± 4.35 cm2, respectively. No statistically significant differences were noted between the sexes. An elaborate radiological examination of the vasculature should be performed prior to surgery to avoid unwanted vascular complications during the anterior approach. Knowing the area of the interarterial and interiliac triangles and the aortic bifurcation location could be aid in assessing the safe working zone.

Methodology for permeability coefficients determination using the vacuum infusion technology

The article describes a special installation allowing real-time determination of the pressure drops within the impregnation process. The installation working zone is a flat permeameter, where the reinforcing material under study is laid, and liquid is supplied. Ultra-low pressure membrane sensors were used to register pressures along the fluid motion direction. Diagram of the sensors installation is provided, as well as substantiation of selecting a site positioned between two adjacent sensors, where it is advisable to conduct the experimental research. Based on the data obtained, the permeability values coefficients were calculated. The article presents results of assessing the accuracy of the proposed method to determine the permeability coefficient values, which was obtained by the authors in comparing experimental and theoretical duration of the impregnation process.

Построение плана траектории перемещения манипуляционного робота на основе модифицированного метода муравьиных колоний

Manipulators are widely used to automate a broad range of operations in industry. It is required to compute a motion plan for a manipulator to move the manipulator from the initial configuration to the goal configuration so that the manipulator can accomplish the planned operations. The motion planning problem is further complicated by the fact that there are obstacles in the work zone of the manipulator, collision with which is to be avoided. There exist many motion planning methods both for obstacle-free environments and for environments with obstacles. The group of motion planning methods based on heuristic algorithms is of a particular interest. In this paper, a research on the possibility of modification of a motion planning method based on ant colony optimization algorithm for building a motion plan for a manipulator is carried out. A modification of the original method, using probabilistic roadmap (PRM) method, is proposed. An analysis on results of modified algorithm with varied values of parameters of the algorithm is performed. Recommendations on the optimal selection of parameters of the algorithm are provided based on results of the analysis.

Regulatory Information Design for Reducing Collision Accidents at the Beginning of Work Zone of Expressway

Regulatory Information Design for Reducing Collision Accidents at the Beginning of Work Zone of Expressway

Evaluating face stability in mountain tunnel excavation by inclination monitoring at the tunnel crown - Atoda tunnel case study

The authors have been developing a prediction method for changes of ground stiffness ahead of a tunnel face by monitoring inclination at the tunnel crown (along the face advance axis). During the Atoda tunnel construction project, inclination monitoring was conducted at measurement intervals of 10 m. This is the first tunneling project practically using the proposed method throughout the excavation length. There is used a newly developed tilt sensor equipped with a Low-Power and Wide-Area (LPWA) wireless communication system that collects inclination data and transmits it to a data gateway automatically. During excavation work zones of weathered and fractured tuff breccia were recognized; face instability and partial collapse were experienced at those locations, though tunnel deformation was generally no more than 10 mm. Inclination values had a tendency to decrease in tunnel advance direction before the face encountered the soft/weak weathered rock, verifying the effectiveness of the method for monitoring tunnel stability and safety.

MIGRANT WORKERS AT MALAYSIAN CONSTRUCTION MARKET: A CRITICAL ANALYSIS OF THEIR FACING DIFFICULTIES

Migrant workers play a significant role to the economy and social development of Malaysia. Most of these employees are working at the construction industry which is known one of the highest hazardous working zones in the globe in terms of personal safety and health. The construction activities comprise various building performances, such as concreting, plastering, paving, bricklaying, painting and other related works. The local people are not much interested to work at this sector. Consequently, Malaysia requires hiring more foreign workers in order to continue the growing demands of building schemes. However, the working situations for those migrant workforces are often challenging but these do not hinder them from working. The aim of this study is to identify and examine some difficulties which are facing by migrant workers in Malaysia. The qualitative method has been used in gathering and analysing of data of this research. This research has found that migrant workers do not achieve some basic legal and humanitarian rights at construction sector in Malaysia. It is submitted that a proper step should be taken to minimise the identified challenges to protect the rights of migrant workers and to influence them to continue working at construction industries in Malaysia.

Road environment characteristics and fatal crash injury during the rush and non-rush hour periods in the U.S: Model testing and cluster analysis

This study aims to assess the relationship between county-level fatal crash injuries and road environmental characteristics at all times of the day and during the rush and non-rush hour periods. We merged eleven-year (2010 - 2020) data from the Fatality Analysis Reporting System. The outcome variable was the county-level fatal crash injury counts. The predictor variables were measures of road types, junction types and work zone, and weather types. We tested the predictiveness of two nested negative binomial models and adjudged that a nested spatial negative binomial regression model outperformed the non-spatial negative binomial model. The median county crash mortality rates at all times of the day and during the rush and non-rush hour periods were 18.4, 7.7, and 10.4 per 100,000 population, respectively. Fatal crash injury rate ratios were significantly elevated on interstates and highways at all times of the day – rush and non-rush hour periods inclusive. Intersections, driveways, and ramps on highways were associated with elevated fatal crash injury rate ratios. Clusters of high fatal crash injury rates were observed in counties located in Montana, Nevada, Colorado, Kansas, New Mexico, Oklahoma, Texas, Arkansas, Mississippi, Alabama, Georgia, and Nevada. The built and natural road environment factors are associated with county-level fatal crash injuries during the rush and non-rush hour periods. Understanding the association of road environment characteristics and the cluster distribution of fatal crash injuries may inform areas in need of focused intervention.

Analysis of construction area’s impacts on traffic flow: A case study on Hangzhou Bay Bridge in China

Modeling impacts of the construction area on the mixed traffic flow would be a challenge. It needs to figure out the traffic regulations near the construction area, which vehicles must comply with. Meanwhile it requires depicting the different driving behaviors of cars and trucks when they run into the construction area. To deal with these problems, we present a three-lane cellular automaton traffic model with a construction area, taking the traffic flow on Hangzhou Bay Bridge with the third lane closed as a case study. The different longitudinal position updating rules and the lateral lane-changing rules are proposed for cars and trucks respectively, which are driven by aggressive drivers and cautious drivers. The simulation results show that the traffic flow will reach the maximum value when the length of the work zone, i.e., the main part of the construction area, is appropriate. On the other hand, the construction area has a great negative impact on the traffic flow when the injection rate is high, and cause the serious traffic congestions. In order to optimize the traffic flow, the variation tendency of the total traffic flow and the delay time with the increasing length of the work zone and the injection rate are analyzed. And the recommended values of the work zone’s length under different injection rates are obtained. In addition, according to the variation trend of the merging rate with the increasing length of the merging area and the injection rate, the recommended values of the merging area’s length under different injection rate are obtained. The results are meaningful and expected to be applied in the traffic management during the period of highway construction.

Simulation of pore space production law and capacity expansion mechanism of underground gas storage

One-dimensional gas injection storage building and one-cycle injection-production modeling experiment, and two-dimensional flat core storage building and multi-cycle injection-production modeling experiment were carried out using one-dimensional long core and large two-dimensional flat physical models to find out the effects of reservoir physical properties and injection-production balance time on reservoir pore utilization efficiency, effective reservoir capacity formation and capacity-reaching cycle. The results show that reservoir physical properties and formation water saturation are the main factors affecting the construction and operation of gas-reservoir type underground gas storage. During the construction and operation of gas-reservoir type gas storage, the reservoir space can be divided into three types of working zones: high efficiency, low efficiency and ineffective ones. The higher the reservoir permeability, the higher the pore utilization efficiency is, the smaller the ineffective working zone is, or there is no ineffective working zone; the smaller the loss of injected gas is, and the higher the utilization rate of pores is. The better the reservoir physical properties, the larger the reservoir space and the larger the final gas storage capacity is. The higher the water saturation of the reservoir, the more the gas loss during gas storage capacity building and operation is. Optimizing injection-production regime to discharge water and reduce water saturation is an effective way to reduce gas loss in gas storage. In the process of multiple cycles of injection and production, there is a reasonable injection-production balance time, further extending the injection-production balance period after reaching the reasonable time has little contribution to the expansion of gas storage capacity.