Research on the Driving Risk Evaluation in Highway Work Zone Section based on Cloud Model

Pakistan has a population of over 199 million and total road network of approximately 264,400 kilometers that serve about 16.2 million vehicles of all types. According to WHO estimates, there were approximately 30,000 annual Road Crash Fatalities (RCF) in Pakistan in year 2010. Work zone crashes account for significant proportion of all traffic crashes in Pakistan due to higher crash rate as compared to other parts of the highway network. Highway work zone is referred to road area where highway construction, maintenance or activity related to utility maintenance takes place. Workers in highway work zone are exposed to a variety of hazards and face risk of injury and death from construction equipment as well as passing motor vehicles. Safety measures and better understanding of risks involved while moving through the work zone have significant effects on the overall safety climate at work zones. Mismanaged work zone traffic increases the travel time delays, safety issues, vehicle operating costs (VOC) and other associated costs. Performance measures for the work zone traffic management includes user costs (travel time delay, crash cost, VOC), incident response and clearance time, queue length and community complaint. Different work Zone Traffic Management methodologies are being practiced worldwide and extensive research has been carried out at international level on country specific highway work zone safety but in Pakistan very few studies have been carried out on highway work zones. This research aims to critically analyze the impacts of the different Work Zone Traffic Management methods and recommend the best option for Expressways / Motorways in Pakistan. For the purpose of research, the author has selected a section of Motorway (M-2). Two different work zone traffic management methods are being followed in rehabilitation of M-2 .i.e. Parallel / Adjacent Method and Median Cross-Over Method. Performance measures selected for purpose of analysis are Travel Time Delay, Crash Cost (Safety) and VOC and data collected on section of M-2. After critical analysis, it is concluded that Parallel/ Adjacent Method results in lesser Travel Time delay and lesser VOC due to higher operating speeds and thus has higher savings, whereas Median Cross over Methods yield more Crash Cost savings. Keeping in view the driving habits / skills, poor maintenance of vehicles in Pakistan and risk of fatal accidents involved in parallel /adjacent method, median cross over method is preferred.

Improving construction work zone safety using technology: A systematic review of applicable technologies

Traffic control is very important for two-lane highway lane-closure work zone traffic management. Control of the open lane’s right of way is very similar to that of a two-phase signalized intersection. Thus, four control strategies including flagger control, pre-timed control proposed by Schonfeld, pre-timed control proposed by Webster, and actuated control are employed for possible use at work zones. Two primary methodologies, the mathematical delay model adopted from signalized intersections, and the simulation model calibrated with field data, are proposed. The simulation and mathematical results show that control strategies for two one-way road intersections could be used for two-lane highway lane-closure work zones. Flagger control after gap-out distance optimization prevails over all the other control strategies in terms of stopped delay, queue length, and throughput, under low or high volumes. Actuated control could be a good alternative for work zone areas due to its small queue length and large vehicle throughput under moderate volume conditions. Our findings may help to optimize the work-zone control strategy and improve operational efficiency at two-lane highway lane-closure work zones.

Speeding in highway work zone: An Evaluation of methods of speed control

Evaluation of emission level increment in urban and sub urban highway work zones

Highway work zone safety has been a concern nationwide and will likely draw ever increasing attention as more highway funds are invested in the maintenance of existing highways. To improve work zone safety, the Indiana Department of Transportation (DOT) established a special fund for work zone patrolling, and this study was commissioned to help the Indiana DOT achieve the maximum safety benefits within its budget constraint. With help from the Indiana DOT, a survey of project engineers was conducted to collect work zone information. The findings from the survey were linked with other available data. A random-effect negative binomial model was developed to identify the contributing factors and to estimate crash frequency in highway work zones. The results from the model provided insight for better understanding of crashes in work zones. Various factors, including roadway information, traffic volume, work zone–specific features, and police presence, were identified as things that affect crash frequency in work zones. These and other findings will be used to plan police enforcement activities in future Indiana DOT work zones.

In highway work zones, lane-changing behaviour near bottlenecks is more urgent than in general segments, referred to as delayed mandatory lane-changing (DMLC). This study proposes an enhanced cellular work zone automata model (DMLC-EWCA) that incorporates DMLC position probability distribution for micro-simulation. Analysing 12 cases from China, the study shows that lane-changing behaviour varies by lane and is influenced by traffic flow and work zone configuration. Extreme value theory is applied to model DMLC position distribution, and lateral lane-changing rules in DMLC-EWCA are improved. The results highlight that traffic flow, speed, and transition area length are key factors influencing vehicle DMLC position. The DMLC-EWCA outperforms the previous CA model at both microscopic and macroscopic levels. A case study applying the DMLC-EWCA optimised transition area length, enhancing innermost lane usage and overall traffic efficiency. The DMLC-EWCA offers a more accurate approach for modelling traffic flow in work zones.

Toward AI-enabled augmented reality to enhance the safety of highway work zones: Feasibility, requirements, and challenges

Analysis of 139 deaths to U.S. female construction workers identified from a death certificate-based surveillance system during 1980-1992 showed that female workers in transportation and material moving had 59 and 85% higher mortality rates than male construction workers in the same occupation from motor vehicles (the leading cause of occupational injury death for women, 43.2%) and machinery (the second leading cause of occupational injury death for women, 15.8%), respectively. Female handlers, equipment cleaners, helpers, and laborers had 73% higher mortality rates than their male counterparts from motor vehicles. Two-thirds of women in construction killed by motor vehicles were pedestrians, compared with an average of 19.2% of women in all industries. Half the female pedestrian decedents in construction were flaggers, compared with 3.4% of construction men killed by motor vehicles. Construction women had higher cause-specific years of potential life lost (to age 65 years) than construction men from motor vehicles (33 vs. 24.8), machinery (29 vs. 24.8), homicide (26.1 vs. 24.6), and falls (31.9 vs, 24.7). Over half (53.2%) the female fatalities occurred before age 35 years, compared with 46% for males. The average fatality rate of 1.80 per 100,000 workers for female construction workers was higher than the rate for women in any other industry. The average rate per 100,000 workers for all industries was 0.77. Further studies are required to explore factors contributing to differences in leading causes of death between female and male construction workers. Development and evaluation of prevention measures, such as effective traffic control in highway construction work zones, fall protection training, and machinery-operation training, could reduce the risks for fatal occupational injuries for construction workers, regardless of gender.

Despite of the fact that the traffic control zone for maintenance work (work zone) has been recognized as one of major priorities to guarantee the traffic safety, only one conventional posted speed limit (PSL) strategy is applied into the organization and management. This article presents the strategy of the variable speed limit (VSL) on highway work zones that brings about gradual deceleration and low speed variance. To evaluate the safety of the proposed VSL strategy, this study uses the microscopic simulation software VISSM to estimate the traffic flow and adopt transversal and longitudinal coefficients of safety (MSDE and cv) to compare the different speed limit strategies. The results of simulation and analysis confirm that VSL yield a substantial decrease the traffic turbulence caused by speed limit and increase the traffic safety throughout work zones.

Law enforcement presence in work zones has long been recognized as one of the most effective speed-reduction methods available to transportation officials. Unfortunately, the design of many work zones makes effective enforcement difficult. Work zones that have no emergency shoulders on either side of the roadway are especially problematic. Incorporating enforcement pullout areas into construction phasing plans has been suggested as a way to improve enforcement activities. However, no guidance had been available on how frequently such enforcement areas should be incorporated. Research was conducted to determine law enforcement and contractor opinions on acceptable spacing criteria for pullout areas in a highway work zone. Two sets of surveys were made by using the Delphi method to solicit the opinions of law enforcement officers and roadway contractors regarding the relative difficulty or effectiveness of pullout areas located at various spacings through a long work zone. The Delphi method was used to quickly bring these groups to consensus. Construction contractors generally were against placing pullout areas closer than 2 mi apart. By contrast, law enforcement officers indicated that at spacing greater than 3 mi, the pullout area would not be useful for traffic enforcement. The results indicate that enforcement pullout areas in work zones should be spaced approximately every 2 to 3 mi or, as an alternative, work zones that eliminate emergency shoulders that are adequate for enforcement purposes should be no longer than 3 mi.

The higher contribution of traffic delay to environmental impacts is urging the highway agencies to take work zone management into the maintenance schemes decision-making. Aiming to understand the role of work zone management in user CO2 emissions reduction, this paper firstly developed a practical methodological framework of traffic delay-related CO2 emissions caused by highway maintenance based on a popular life cycle user cost analysis approach in regard of the microscopic vehicle operation analysis. The method was applied in an actual freeway flexible pavement with 15-year design life in Shaanxi Province, China, covering three types of preventive maintenance, correction maintenance, and rehabilitation. In addition, the impacts of key inputs of proposed method on work zone user CO2 emissions results were checked. The results show that traffic delay attributes to 29.4% of total CO2 emissions of the life cycle of highway pavement maintenance, and 51.8% of work zone user CO2 emissions result from preventive maintenance, especially from micro vehicle operations including speed change and queue near work zone (62% of total work zone user CO2 emissions). The work zone management alternative strategies related to less traffic volume or higher highway capacity including vehicle type limitation and the limited work zone speed have an advantage in reducing the work zone CO2 emissions over changing work zone length or work zone timing. The findings in this paper may present a useful tool and reference for robustly supporting the decision-making on highway maintenance carbon mitigation in work zone traffic.

Construction work zones are inevitable parts of daily operations at roadway systems. They have a significant impact on traffic conditions and the mobility of roadway systems. The traffic impacts of work zones could significantly vary due to several interacting factors such as work zone factors (work zone location and layout, length of the closure, work zone speed, intensity, and daily active hours); traffic factors (percentage of heavy vehicles, highway speed limit, capacity, mobility, flow, density, congestion, and occupancy); road factors (number of total lanes, number of open lanes, and pavement grade and condition); temporal factors (e.g., year, season, month, weekday, daytime, and darkness); weather conditions (rainy, sunny, and snowy); and spatial factors (road lane width, proximity, and number of ramps). Utah Department of Transportation (UDOT) is continuously collecting and storing project-related data. Due to the significant impact of work zones on traffic conditions, they are interested in evaluating the impacts of work zone attributes on mobility and traffic conditions of roadway systems within the state of Utah. Such an analysis will help the UDOT personnel better understand and plan for more efficient work zone operations, select the most effective traffic management systems for work zones, and assess the hidden costs of construction operations at work zones. To help UDOT address this problem, we propose a robust, deep neural network (DNN) model capable of evaluating the impacts of the factors mentioned earlier on the mobility conditions of Utah roadway systems. DNNs can capture all the relationships between input variables and output compared to traditional machine learning algorithms. The results of this project show that work zone features have an important effect on the traffic condition. In the end, the performance of the model is evaluated using three different measures, including R2 score, RMSE, and MAE. Comparing the measurement to previously conducted research, it is the first study that has attempted to investigate the effect of work zone features on hourly traffic volume.

Physical ergonomic hazards in highway tunnel construction: Overview from the Construction Occupational Health Program

Construction sites or work zones create serious disruptions in the normal flow of traffic, resulting in major inconveniences for the traveling public. Furthermore, these work zones create safety hazards that require special consideration. Current legislation and programs, at both state and national levels, emphasize the need for a better understanding of work zone problems to address work zone safety. This reality—coupled with the temporary closure of more miles of highway every year for rehabilitation and maintenance—makes the analysis of safety at construction sites a serious matter. A summary of a comprehensive study associated with the development of a new practical approach to address highway safety in construction zones is presented. Because empirical models require sample sizes that are not attainable due to the intrinsic scarcity of construction zone accident data, the problem was studied from the point of view of risk analysis. Monte Carlo simulations were used to develop risk factors. These factors are meant to be included in the calculations of additional user costs for work zones, or simply applied as risk measurements, to optimize the length and duration of closures for highway reconstruction and rehabilitation projects. In this way, it will be possible to assess the danger of work zones to the traveling public and minimize adverse effect of work zones on highway safety.