Median Barrier Research Articles

Enhancing road safety with the infrastructure-adaptable NDBA 2.0 concrete median barrier: An Italian experience

Road safety is a crucial global concern because of the high number of fatalities and injuries resulting from road crashes each year. Median crossover collisions are among the most dangerous crashes that happen on highways, frequently leading to serious or fatal injuries. The main approach to decreasing the occurrence of these types of crashes is the installation of median barriers. When the need for such installations arises, road agencies must choose from various options, including concrete barriers, cable barriers, or metal-beam guardrails. This paper is dedicated to the New Dynamic Barrier for Highways (NDBA 2.0), an innovative technology for median barriers developed by the Italian National Road Agency (ANAS), emphasizing its pivotal role in enhancing road safety. It incorporates high-tensile steel and advanced composites, offering robust protection while maintaining a lightweight profile. What distinguishes the NDBA 2.0 is its dynamic nature, featuring an intelligent system that seamlessly adapts to the road infrastructure. Its modular construction, with sections of only 200 cm, allows for easy installation and ensures compatibility across successive road segments. This adaptability reduces construction time while maintaining the highest standards of performance. From a road safety perspective, the NDBA 2.0 offers substantial advantages. Its design contributes to minimizing crash-related costs by reducing the severity of crashes, particularly in the transition zones. The barrier's design allows it to adapt to varying road conditions and traffic volumes, effectively addressing common installation challenges on existing roadways as well. Its ability to be directly supported on the road surface wear layer eliminates the need for costly foundation structures, facilitating quick installation and reducing maintenance expenses. The NDBA 2.0 barrier was designed to eliminate the need for future simulations in the design and verification of transitions between different barriers. For this reason, the NDBA 2.0 barrier has been tested in real-world conditions in class H4 and, consequently, is equipped with CE marking. This study offers a comprehensive analysis of the NDBA 2.0 barrier, whose implementation may provide significant benefits for road safety. Continued research, collaboration, and widespread adoption of the NDBA 2.0 barrier can further enhance road safety on a global scale.

A national survey on assessment of knowledge, perceptions, practice, and barriers among hospital pharmacists towards medication reconciliation in United Arab Emirates

Medication reconciliation (MedRec) helps prevent medication errors. This cross-sectional, nationwide study assessed the knowledge, perceptions, practice, and barriers toward MedRec amongst hospital pharmacy practitioners in the United Arab Emirates. A total of 342 conveniently chosen stratified hospital pharmacists responded to the online survey (88.6% response rate). Mann–Whitney U test and Kruskal–Wallis test were applied at alpha = 0.05 and post hoc analysis was performed using Bonferroni test. The overall median knowledge score was 9/12 with IQR (9–11) with higher levels among clinical pharmacists (p < 0.001) and previously trained pharmacists (p < 0.001). Of the respondents, 35.09% (n = 120) practiced MedRec for fewer than five patients per week despite having a strong perception of their role in this process. The overall median perception score was 32.5/35 IQR (28–35) with higher scores among clinical pharmacists (p < 0.001) and those who attended previous training or workshops (p < 0.001). The median barrier score was 24/30 with an IQR (21–25), where lack of training and knowledge were the most common barriers. Results showed that pharmacists who did not attend previous training or workshops on MedRec had higher barrier levels than those who attended (p = 0.012). This study emphasizes the significance of tackling knowledge gaps, aligning perceptions with practice, and suggesting educational interventions.

Development of an overlaid concrete median barrier: Numerical studies and full-scale field tests

This study aims to develop an overlaid CMB(Concrete Median Barrier) with a containment level of SB5 (230 kJ of impact severity) based on a series of numerical simulations and full-scale field tests. The 810-mm CMB (CMB810) currently in service on roads, should be overlaid up to height of 1370 mm (CMB1370) with containment level of SB5 to prevent vehicles from traveling over it. From a series of numerical simulation, the effects of dowel/longitudinal bars on structural adequacy and occupant risk were quantitatively assessed in order to develop the CMB1370. Numerical analyses indicate that decreasing the spacing of dowel bars and the proximity of longitudinal bars from the top of the CMB1370 can significantly lessen the volume loss incurred during vehicle-to-barrier collisions. The numerically proposed CMB1370 underwent full-scale field tests in compliance with three evaluation criteria: (1) structural adequacy, (2) occupant risk, (3) vehicle's post-impact trajectory. The full-scale field test results demonstrated that the CMB1370 effectively contained and redirected the vehicle without any instance of damages, penetration or overriding. The measured deformation of CMB1370 by several LVDTs was within acceptable limits for use on the road. Previous full-scale field tests, the primary focus was on the structural adequacy of the CMB and the resulting damage it sustained. However, these findings provide new insights into the behavior and rehabilitation of the CMB, as well as the damage sustained at impact. Moreover, no significantly fragmented debris larger than 2.0 kg was observed from the barrier. Thus, the proposed CMB1370 meets all the requirements specified in the crash test guidelines in Korea.

Exploring interacting effects of risk factors on run-off-road crash severity: An interpretable machine learning model joint with latent class clustering

Run-Off-Road (ROR) crashes are frequent and pose a significant risk of injury and fatality. Given the complexity of their mechanisms and the interaction of multiple factors, this study aims to comprehensively investigate the factors influencing the severity of ROR crashes, which have been understudied. Furthermore, addressing the current methodological challenge in machine learning (ML) crash modeling, this study proposes an approach to tackle unobserved heterogeneity in ML. An interpretable ML joint with prior latent class clustering is implemented. The significant risk factors and interactions are interpreted using SHAP (SHapley Additive exPlanations) method across clusters. This study utilizes ROR crash records, traffic, and geometric data from main suburban freeways in Iran collected over a 5-year period. The key interacting factors associated with severe ROR during adverse weather (cluster 1) are: co-occurrence of low congestion and higher speed variation; low congestion, nighttime darkness and rollover; roadway departure by buses and mini-buses and rollover occurrence; vehicle departure and collision with fixed objects. Moreover, the critical interactions for nighttime condition (cluster 2) are: curve sections combined with longitudinal slope; inside shoulder width <1.5 m and a hit median concrete NewJersey barrier. The risky interactions for crashes occurred in curves (cluster 3) are: departing in two-lane sections in low congestion conditions; vehicles collisions with the median concrete NewJersey barriers. The findings of this study enhance comprehension of the significant effects of interactions under various conditions, offering valuable insights for policymakers. Additionally, recommendations are offered to mitigate the risk of severe ROR crashes.

Evaluation of the physical barrier on lane segregation at multilane highway towards motorcyclist: A case study

Abstract In Malaysia, the escalating annual road traffic accidents, primarily attributed to human factors, necessitate a closer examination of these influences. This study focuses on assessing the impact of lane segregation on motorcyclists’ behavior within multilane roadways. Conducted along the R5 highway from Kapar to Kuala Selangor, classified as a rural highway, the study evaluates the 85th percentile operating speed, crucial for multilane flow rate. Two locations, one with median physical barriers and the other with only line markings, were compared. Traffic flow and speed were observed at 5-minute intervals over 45 minutes using a laser gun and tally counter. Analysis, based on the Malaysian Highway Capacity Manual, revealed that the median barrier location promoted safe speeds and a higher motorcycle percentage. Conversely, the absence of a median barrier but with line markings resulted in elevated speeds exceeding the limit, accompanied by a lower motorcycle percentage. These findings underscore the significance of median physical barriers in reducing vehicle speed, enhancing road safety, and curbing road accidents.

A holistic optimization-based approach for sustainable selection of level crossings for closure with safety, economic, and environmental considerations

An intersection of railway and highway segments at the same elevation, known as a highway-rail grade crossing or level crossing, presents significant safety concerns and operational challenges. To mitigate these issues, different methods can be adopted, such as implementation of countermeasures (e.g., installation of flashing lights, gates, and median barriers), grade separations, and level crossing closures. The closure of selected level crossings, when done thoughtfully in consultation with relevant stakeholders and affected communities, can be a highly effective alternative. However, the majority of studies in this field primarily focuses on the implementation of countermeasures and mainly concentrates on safety-related aspects. Considering the drawbacks in the current research, a novel optimization model to identify level crossings for closure is presented in this study, which evaluates various benefits from closing specifically selected level crossings, including safety, economic, and environmental benefits, as well as reduction in traffic delays and maintenance and operational costs. A specialized heuristic algorithm inspired by sorting principles is developed to solve the decision problem addressed in this study. A set of comprehensive computational experiments are performed focusing on level crossings situated in the State of Florida (United States). The findings show clear superiority of the developed heuristic algorithm against the exact method, as it was able to solve the generated problem instances ≈20 times faster with the average optimality gap of only 0.14 %. Additionally, various sensitivity analyses are performed to illustrate managerial implications from the implementation of the proposed optimization approach to administer closures of level crossings.

Wildlife mortality risk posed by high and low traffic roads.

Wildlife mortality due to collisions with vehicles (roadkill) is one of the predominant negative effects exerted by roads on many wildlife species. Reducing roadkill is therefore a major component of wildlife conservation. Roadkill is affected by various factors, including road attributes and traffic volume. It is theorized that the effect of traffic volume on roadkill probability should be unimodal. However, empirical evidence for this theory is lacking. Using a large-scale roadkill database of 18 wildlife species in Israel, encompassing 2846km of roads over 10years, we explored the effects of traffic volume and road attributes (e.g., road lighting, verge vegetation) on roadkill probability with a multivariate generalized linear mixed model. A unimodal effect of traffic volume was identified for the striped hyena (Hyaena hyaena), whereas 5 species demonstrated a novel quadratic U-shaped effect (e.g., golden jackal [Canis aureus]). Four species showed a negative linear effect (e.g., wild boar [Sus scrofa]). We also identified varying effects of road attributes on roadkill. For instance, road lighting and roadside trees decreased roadkill for several species, whereas bus stops and concrete guardrails led to increased roadkill. The theorized unimodal effect of traffic volume may only apply to large, agile species, and the U-shaped effect could be related to intraspecies variability in traffic avoidance behavior. In general, we found that both high-traffic and low-traffic roads can pose a high mortality risk for wildlife. It is therefore important to monitor roadkill on low-traffic roads and adapt road attributes to mitigate roadkill. Road design for effective roadkill mitigation includes reducing the use of concrete guardrails and median barriers where possible and avoiding dense bushes in verge landscaping. These measures are complemented by employing wildlife detection systems, driver warnings, and seasonal speed reduction measures on low-traffic roads identified as roadkill hotspots.

Investigating safety and cost-effectiveness of cable median barriers in Louisiana

Objectives Cable median barriers (CMBs) are installed on freeway medians to prevent cross-median crashes and reduce the severity of median-related crashes. Though CMBs are effective in preventing cross-median crashes, they are also known to increase the number of property damage–only (PDO) crashes. The higher frequency of PDO crashes could result in increased CMB maintenance and repair expenses. The aim of this study is to evaluate the safety impact and economic justification of CMBs in Louisiana. Methods Initially, a flowchart was developed using Louisiana crash data to identify targeted crashes, such as median-related and cross-median crashes. This was followed by a 3-year observational before-and-after crash analysis with an emphasis on head-on collisions and crashes involving large trucks. Using a 4-step improved prediction method, crash modification factors were then developed to quantitatively assess the impact of CMBs on crash outcomes, accounting for and adjusting to changes in the annual average daily traffic (AADT) and relevant crash frequencies before and after CMB implementation. Finally, an exhaustive benefit–cost analysis was conducted to determine the cost-effectiveness of CMBs. Results The results revealed that CMBs significantly reduced cross-median crashes of all severities. However, an increase in PDO crashes was observed in both total and median-related crashes. Large truck cross-median crashes and head-on collisions also decreased significantly after CMB implementation. Testing Level 4 (TL-4) CMBs were found to be more effective in preventing vehicles from crossing the median and in reducing crashes of higher severity levels. The benefit–cost ratios, calculated using economic crash unit costs for both total and targeted crashes, were greater than 1. Notably, the estimated benefit–cost ratios were considerably higher, demonstrating that CMBs are cost-effective countermeasures for enhancing traffic safety. Conclusion This study contributes to the understanding of CMB performance from both traffic safety and economic perspectives. The findings may assist transportation agencies in making decisions regarding the management of CMB systems. Based on the comprehensive analysis of CMBs on Louisiana freeways, this project has revealed that CMBs are an effective and economically justified crash countermeasure. Thus, further implementation of CMBs is recommended until better alternatives are available.

Numerical modeling and simulation of cable barriers under vehicular impacts on a sloped median

Cable barriers are flexible barrier systems that are commonly used as median barriers in the United States for their general effectiveness and low installation and maintenance costs. The current cable median barrier (CMB) adopted by the North Carolina Department of Transportation was previously evaluated on flat terrain and found to satisfy the requirements of the National Cooperative Highway Research Program Report 350. Under in-service conditions (i.e., on a sloped median), the current CMB failed to stop small passenger cars in many incidents. The new roadside safety standard, Manual for Assessing Safety Hardware (MASH), recommends that CMBs be tested and/or evaluated on sloped medians. However, conducting full-scale crash tests on sloped median is extremely difficult and few experimental studies exist. In this study, finite element simulations were used to evaluate the performance of the current CMB design on a 6H:1V sloped median under MASH Test Level 3 conditions. To address the issue of vehicle underriding on the current CMB, two retrofit designs were developed and also evaluated on the sloped median. Two MASH compliant vehicles, a 1996 Dodge Neon and a 2006 Ford F250, were used to evaluate all three CMBs from both frontside and backside and with two initial impact points. The MASH exit-box criterion, MASH Evaluation criteria A, D, and F, vehicular responses, exit angles, and residual velocities were used to evaluate the CMB performance for structural adequacy, occupant risk, and post-impact trajectories. The simulation results showed that one of the retrofit designs could improve the CMB performance on a sloped median at MASH Test Level 3 conditions.

Barriers and Stimulus in Shared Decision Making Among Aesthetic Dermatologists in China: Findings from a Cross-Sectional Study.

Shared decision making (SDM) is a collaborative process involving both healthcare providers and patients in making medical decisions, which gains increasing prominence in healthcare practice. But evidence on the level of SDM in medical practice and barriers as well as stimulus during the SDM implementation among aesthetic dermatologists is limited in China. From July to August 2023, 1938 dermatologists were recruited online in China. Data were collected through an electronic questionnaire covering: (1) demographic features; (2) SDM questionnaire physician version (SDM-Q-Doc); and (3) stimulus and barriers in SDM implementation. Logistic regression was applied to explore factors associated with SDM practice, barriers, and stimulus of SDM implementation, respectively. The 1938 dermatologists included 1329 females (68.6%), with an average age of 35 years. The total SDM score ranged from 0 to 45, with a median value of 40 (IQR: 35-44), and the median stimulus score and barriers scores were 28 (IQR: 24-32) and 19 (IQR: 13-26), respectively. The prevalence of good SDM was 27.2%, logistic regression indicated that female dermatologists (odds ratio, OR=1.21, 95% confidence interval, CI: 0.96-1.51), and dermatologists with more years of aesthetic practice had a higher proportion of good SDM practice (OR was 1.44 for 5-9 years, 1.58 for 10-15 years and 1.77 for over 15 years). Moreover, female dermatologists and dermatologists with higher education level and serviced in private settings had lower barrier scores; female dermatologists and dermatologists with more years of aesthetic practice had higher stimulus scores. Chinese aesthetic dermatologists appear to implement SDM at an active level, with more stimulus and less barriers in SDM implementation. The integration of SDM into clinical practice among dermatologists is beneficial both for patients and dermatologists. Moreover, SDM practice should be strongly promoted and enhanced during medical aesthetics, especially among male dermatologists, dermatologists with less working experience, and those who work at public institutions.

Are crash causation studies the best way to understand system failures – Who can we blame?

The search for common and serious single causes of road crashes naturally leads to a concentration on the road user. This is supported by a legal framework in the search for the main cause and the suspect for this cause.In prevention, we havefor decades been more inclined to look for systematic improvements of all elements of the road transport system, and we direct the recommendations for actions towards system designers, organizations, products and services.In this paper the discussion about causation and prevention is broadened in the light of Vision Zero and its approach to prevention of serious and fatal injuries. We also discuss the Swedish judicial system and why the prevention approach has not been legislated or even generally accepted. Occupational health and safety legislation and road rules are compared, as well as how sustainability practices and reporting are tools to apply prevention where organizations have a natural sphere of influence that could mitigate deaths and serious injuries within value chains.It is recommended that we stop using the term causation as it is only directing actions in one direction. There is a risk that the focus on causation, in particular single causes, will deviate actions away from robust prevention countermeasures such as increased seat belt use, relevant speed limits, and well functioning roundabouts and median barriers. Furthermore, there is also a risk that important preventative actions from organizations are overlooked.

Development of an SB4-grade Separated Concrete Median Barrier using a Collision Analysis Model

Development of an SB4-grade Separated Concrete Median Barrier using a Collision Analysis Model

Bronx-Whitestone Bridge: Vertical median barrier extension enhances aerodynamics

The Bronx-Whitestone Bridge was designed during the 1930s in an era of suspension bridges with decks stiffened by shallow plate girders, many of which were subsequently found to be vulnerable to aerodynamic instabilities such as vortex shedding and flutter. Following the occurrence of mild and benign wind-induced oscillations in the first several years after opening in 1939, the bridge has undergone a series of retrofits, from structural solutions such as stay cables, stiffening trusses, and a steel orthotropic deck, to aerodynamic enhancements such as a tuned mass damper and wind fairings. Wind tunnel studies in 2015 confirmed the improved aerodynamic performance due to the recently installed wind fairing system and stiffer orthotropic deck. A subsequent rehabilitation project gave the opportunity to assess measures to further improve the aerodynamic performance of the bridge. A 3 ft (0.91 m) tall solid screen added on top of the median barrier was found to act as an above-deck vertical baffle plate, disrupting the alternating pattern of vortices, reducing the susceptibility of the bridge to instabilities. This led to the conceptual design of a Median Barrier Extension (MBE) comprised of 3 ft (0.91 m) solid transparent acrylic panels fixed to the top of the existing median barrier posts, supported by a tubular steel frame. To ensure this unique barrier modification met current industry safety standards, the MBE design was iterated through a crash analysis study using non-linear finite element models before the final design proceeded to a full-scale physical crash testing program to MASH Test Level 4. This paper presents the full timeline of this innovative retrofit project, from conception during wind tunnel testing, through to design, crashworthiness studies and final construction in 2020. This project has demonstrated that a vertical extension to a median barrier can act as a simple and cost-effective enhancement to the aerodynamic performance of existing bridges.

SEMA6A drives GnRH neuron-dependent puberty onset by tuning median eminence vascular permeability

Innervation of the hypothalamic median eminence by Gonadotropin-Releasing Hormone (GnRH) neurons is vital to ensure puberty onset and successful reproduction. However, the molecular and cellular mechanisms underlying median eminence development and pubertal timing are incompletely understood. Here we show that Semaphorin-6A is strongly expressed by median eminence-resident oligodendrocytes positioned adjacent to GnRH neuron projections and fenestrated capillaries, and that Semaphorin-6A is required for GnRH neuron innervation and puberty onset. In vitro and in vivo experiments reveal an unexpected function for Semaphorin-6A, via its receptor Plexin-A2, in the control of median eminence vascular permeability to maintain neuroendocrine homeostasis. To support the significance of these findings in humans, we identify patients with delayed puberty carrying a novel pathogenic variant of SEMA6A. In all, our data reveal a role for Semaphorin-6A in regulating GnRH neuron patterning by tuning the median eminence vascular barrier and thereby controlling puberty onset.

Numerical and Experimental Analysis to Develop a SB6/H3 High Containment Level Concrete Median Barrier

As the number of heavy vehicles on the road continues to increase, collisions involving heavy vehicles and concrete median barriers (CMB) occur more frequently than in the past. Consequently, there is a growing need for research into more stringent design standards and improvements to the current CMB and their performance under harsh conditions. High-performance CMB is required to in order to withstand such conditions. This paper presents the results of numerical simulations and full-scale field tests to develop a high-performance CMB. To facilitate the development of the high-performance CMB, the concept of a deformable CMB was applied to the rigid CMB. A new apparatus called the shock absorber composed of dowel bars surrounded by empty space were introduced to make the rigid CMB deformable. In order to prevent local failure at the top of the barrier from a sudden high increase in impact energy, the deformable CMB was strengthened by adding reinforcements and widening the top based on the results of numerical simulations. The full-scale field tests were conducted on the proposed deformable CMB and took into account three appraisal areas: (1) structural adequacy, (2) occupant risk, and (3) vehicle trajectory after collision. The results of these tests showed that the deformable CMB contained and redirected the vehicle without allowing it to penetrate or override the deformable CMB. No detached elements, fragmentation, or other debris from the barrier were present. Therefore, the proposed high-performance CMB fulfilled all of the requirements of the crash test guideline.

A national survey of knowledge, attitude, practice, and barriers towards pharmacovigilance and adverse drug reaction reporting among hospital pharmacy practitioners in the United Arab Emirates

BackgroundPharmacovigilance (PV) is an essential component of patient safety and pharmacists are expected to be aware of the PV processes and willing to report ADRs. This study assessed the hospital pharmacists’ knowledge, attitude, and practice toward PV, barriers faced by them in ADR reporting, and factors influencing ADR reporting.MethodA cross-sectional nationwide questionnaire survey was conducted among randomly chosen hospital pharmacists across UAE from March to July 2022. The filled questionnaires were assessed both descriptively [median (IQR scores), maximum 5 for Likert type and 1 for knowledge questions] and inferentially using the Mann–Whitney U test (for dichotomous variables) and the Kruskal–Wallis test (for variables with more than two responses) at alpha value = 0.05. Post hoc analyses and correlations were performed wherever applicable.ResultsOf the 342 respondents, the majority were knowledgeable about the concepts of PV (93.3%; n = 319) and ADRs (86.8%; n = 297). The overall median (IQR) knowledge score was 5 (3–7)/9. Knowledge levels within ‘qualification groups’ varied significantly (p-value < 0.001) and participants ‘between 10 and 14 years of experience’ had more knowledge than those ‘with < 5 years of experience’ (p-value < 0.001, Bonferroni test). The overall median (IQR) attitude score was 22 (20–24)/30. Most respondents (90.6%; n = 311) were willing to spare time to review patients’ ADR reports. The overall median (IQR) practice score was 17.5 (11–21)/24. Although 71.1% (n = 243) noticed ADRs during the previous year, only 53.2% (n = 182) reported an ADR, the reasons for underreporting being mainly due to a lack of proper training [median IQR score 4(4–5)/5]. The ‘clinical pharmacists’ engaged themselves more in pharmacovigilance than ‘pharmacists’ (p-value = < 0.001), and ‘inpatient pharmacists’ reported more ADRs than ‘pharmacists’ (p-value = 0.018); Bonferroni test. The overall median (IQR) barrier score was 26 (23–29)/40 and the common barrier was ‘lack of awareness about the national ADR reporting system 4 (4–5)’. The pharmacists in this study suggested incentives for reporting ADRs (69.3%; n = 237).ConclusionThe authors concluded professional training courses for practicing pharmacists and educational curriculums related to PV and ADR reporting processes are to be considered for future pharmacists in order to inculcate ADR reporting culture and practices.

A Random Parameters Multinomial Logit Model Analysis of Median Barrier Crash Injury Severity on Wyoming Interstates

This paper investigated factors influencing injury severity of crashes involving median traffic barriers, including the impact of barrier characteristics and their geometric features in Wyoming. Combining field data of inventoried median barriers with crash data on Wyoming interstates highways, a random parameters multinomial logit (mixed logit) model of injury severity was estimated. This methodological approach allowed for the possibility of estimated model parameters to vary randomly across crash observations to account for heterogeneity with respect to driver characteristics, roadway attributes, and vehicle characteristics. The estimation results indicated concrete barriers installed on front side-slopes and box beam barriers were associated with severe injury crashes. It was also found that median barrier crashes involving sports utility vehicles, pickups, and improperly restraint vehicle occupants are complex and vary significantly across observations. Other statistically significant variables found to increase the likelihood of severe injury crashes were rural interstate roads, concrete barriers installed on a front side-slope, box beam barriers with lateral offset less than 2 feet, and rollover crashes. These parameters were fixed across observations. The findings of this research point to the need to further investigate the impacts of sport utility vehicles, pickups, and rollover crashes on median barrier crash injury severity.

A Study On the Effectiveness of Rolling Barrier System at Straight Road and Curved Road: A Review

The rolling barrier system is part of the road safety infrastructure that is used to improve and maintain road safety. It is also possible to overcome and reduce the number of crashes. A rolling barrier is a type of safety device that not only absorbs but also converts shock energy into rotational energy, thereby preventing fatal accidents for drivers and passengers. A rolling barrier should be installed in areas where vehicles are frequently collided. By absorbing shock energy, a rolling barrier will safely guide a vehicle back to the road or stopped the vehicle. This study was built on the findings of a previous study to determine the effectiveness of a rolling barrier system for use on both straight and curved roads. This research focuses on a new invention, the rolling barrier system, as opposed to the traditional barrier, in order to learn more about its mechanism and function. The study's scope was limited to focusing on the implementation of the rolling barrier system on straight and curved roads. According to the previous study, straight and curved roads have the highest incident rates compared to other types of roads. The Rolling Barrier System was strategically installed in three high-risk areas with a high incidence of fatal traffic incidents. The three high-risk road locations that require additional safety are straight roads, curving roads, and hilly roads, which are the most important locations to place Rolling Barrier Systems in order to decrease high-risk accidents and fatalities while also improving road safety. There are four types of roads that are appropriate for implementing a Rolling Barrier System. The Rolling Barrier types are straight roadside Rolling Barriers, curved roadside Rolling Barriers, steep roadside Rolling Barriers, and median Rolling Barriers.

Serviceability Analysis of Pedestrian Overhead Bridges and Underpasses

A grade-separated crossing allows a bicycle/pedestrian to continue over or under a barrier without conflict with a vehicle. However, the serviceability of these facilities is compromised in underdeveloped countries, including Pakistan. This research examines the effectiveness of pedestrian bridges and underpasses in terms of their usage by pedestrians. A total of 80,017 pedestrian crossings were observed at four sites (3 overhead bridges and one underpass) for four weeks (one week per site) using manual and video photography. The data about age, gender, and serviceability of each pedestrian was collected and analyzed using the chi-square test, t-test, and descriptive analysis. The study site selection was based on different characteristics, i.e., the number of lanes, type of median barriers, and type of facility (bridge/underpass). The analysis shows that most of the pedestrians (71.83%) did not use the crossing facilities, resulting in the poor serviceability of these structures. A comparison between bridges and underpasses also reveals that underpass usage (62.5%) is statistically more significant than bridge usage (11.62%). There is an effect of age (p&lt;0.001) and gender (p&lt;0.001) on the serviceability of these facilities as well, with pedestrians aged more than 25 years old and females using the facilities more than their counterparts. The study also provides implications for the effect of barriers and the height of facilities on the serviceability of these facilities. The number of lanes and the presence of a median barrier, as well as the height of the facility (number of steps), are the primary factors influencing the serviceability of grade-separated pedestrian crossings. Doi: 10.28991/CEJ-2023-09-04-09 Full Text: PDF

Exploring determinants of log truck accidents resulting in injury or fatality in the Northwest United States between 2015-2019 using Motor Carrier Management Information System data

ABSTRACT Log truck drivers represent a high-risk yet understudied worker population. Logging, more generally, is known to be one of the most dangerous industries in the country, but little is known about injury and fatality rates among log truck drivers specifically. Using data from the Motor Carrier Management Information System (MCMIS), this study aims to characterize log truck crashes in Washington, Oregon, Idaho, and Montana. Using multiple logistic regression, we estimated the odds of a crash resulting in an injury or fatality by environmental and structural conditions at the time of each crash. Results indicate that the presence of a positive median barrier is strongly associated with a decreased odds of injury or fatality for log truck crashes (odds ratio (OR) = 0.45, p = 0.03). An increased number of vehicles involved in the crash was significantly associated with an increased odds of injury or fatality (OR = 1.32, p = 0.01). Crashes occurring in Washington or Oregon had significantly decreased odds of resulting in an injury or fatality, in comparison to Idaho and Montana (OR = 0.14, p < 0.001; OR = 0.53, p = 0.01, respectively). These results indicate that the presence of highway safety measures and a state-approved OSHA plan may be beneficial in decreasing the odds of injury or fatality in log truck crashes.