To characterize the distribution, risks, and geospatial attributes of truck driver at-work deaths. At-work medical examiner death data from Harris County, Texas were extracted and analyzed using a case-control design. Truck driver cases (n = 52) were matched on age characteristics to non-truck driver controls (n = 156). These data included place of injury/collapse, manner of death, anthropometrics, and demographics. Medical center and American Community Survey data were extracted for geospatial analyses. Truck driver at-work deaths differed from controls in the distribution of manners of death, and they occurred more commonly in underserved census tracts. Truck driver at-work deaths were predicted by both of these differences. These findings provide preliminary evidence for truck driver vulnerability to natural deaths at work and the characterization of truck driver worksites as medical deserts.
Longue-distance trucks drivers are a population at increased risk of HIV infection compared with the general population. This study aimed to estimate the national prevalence of HIV and identify factors associated with infection among longue-distance trucks drivers in Mali. We conducted a cross-sectional bio-behavioral survey using Time-Location Sampling (TLS) between July 2019 and February 2020. Eligible participants were truck drivers aged ≥ 18 years who regularly undertook long-distance trips (at least 200 km one way). Following pre-test counseling, HIV testing was performed according to national testing algorithm, using Determine as the screening test and SD Bioline for confirmation. Data were analyzed using SPSS version 25. Written informed consent was obtained from all participants. A total of 1,100 participants were included in the study. Most participants were aged ≥ 20 years (91.5%), 63.5% had received formal education, and 57.2% were married. Risk behaviors were common: 37.7% reported having multiple sexual partners, 23.5% reported drug use before sexual intercourse, 44.6% reported condom use during their last sexual intercourse, and 51.8% reported spending more than one month away from home. Although 78.8% recognized condoms use a protective measure against HIV infection, preventive practices remained inconsistent. The national HIV prevalence was 1.9%. Higher prevalence estimates were observed in the regions of Ségou (2.7%), Sikasso (2.6%), and Koulikoro region (2%). In bivariate analyses, HIV infection was significantly associated with older age (median 38 vs. 31 years; p = 0.002), marital status (p = 0.002), education level (p = 0.015), and longer work experience (p = 0.001). In multivariate analysis, no factors remained statistical significance. However, longer work experience (> 5 years) was associated with higher odds of HIV infection (adjusted odds ratio [aOR] = 3.68; 95% CI: 0.93-21.27), whereas formal education appeared to have a protective effect (aOR = 0.54; 95% CI: 0.21-1.29). HIV prevalence among long-distance truck drivers in Mali remains higher than reported in the general population, alongside persistent high-risk behaviors and regional disparities. Targeted, context-specific preventive measures are urgently needed to reduce new infections in this highly mobile and vulnerable population.
The Canadian trucking industry employs over 300,000 long-haul truck drivers (LHTD) and has the highest number of worker compensation claims of any industry in Canada. Although studies have shown associations between obesity, decreased workplace productivity, and cognitive impairment in the general population, there is limited information on these relationships among LHTD. This pilot study aimed to: (1) profile LHTD health, demographics, and clinical test scores; (2) examine associations between obesity and workplace productivity; and (3) explore connections between obesity and clinical assessment test scores. LHTD were recruited from various provincial and federal trucking associations and companies across Canada. In total, 36 LHTD completed a demographic questionnaire that surveyed their work, driving history, and health, followed by a few objective health measures (e.g., height; weight; blood pressure), as well as a battery of cognitive (e.g., Trail Making Test A and B; Montreal Cognitive Assessment; Useful Field of View; Clock Draw Test), visual (e.g., visual acuity; contrast sensitivity), and motor (e.g., Rapid Pace Walk) tests. Over half of the sample (63.9%) were obese (BMI greater than 30.0 kg/m2). Obese LHTD took significantly more sick days (p = .022), worked significantly more while sick and injured (p = .006 and p = .039, respectively), had significantly more crashes (p = .014), and exhibited poorer divided attention/concentration (p = .014), compared to non-obese LHTD.Conclusions/Applications to Practice:The findings show that obesity can impact worker productivity in LHTD, but the complex interplay between cognition, obesity, and worker productivity warrants further investigation.
Tow truck drivers (TTD) are often the first to present at vehicle crashes, in addition to police, ambulance and at times fire services. Existing research suggests that TTD do not always receive similar supports as other first responders. A gap highlighted the need to understand the physical and psychological experiences of TTD, how they manage challenges and what supports they receive. The aim of the study is to understand why TTD should be considered first responders and to explore experiences related to the challenges encountered in their work. A scoping review was conducted to address the aims of the study using the PRISMA for scoping reviews guidelines to ensure accurate and rigorous reporting of findings. A broad literature search was conducted between February and April 2024, using the databases PubMed, Scopus, CINAHL and EBSCO (Newspaper Source Plus), while also searching Google Scholar search engine to identify sources related to TTD. Studies of TTD were included if they were original research, written in English, peer-reviewed or news reports. Studies were excluded if truck drivers were not related to the tow truck industry. A total of 14 studies were included in the review. No specific key attributes for TTD were reported; however, they were found to be the first on the scene following an accident due to their well-developed network. TTD experience physical and psychological trauma. Support services are limited, and poor coping strategies, such as excessive alcohol intake, are reported. Lack of safety training was considered a contributor of occupational hazards in the industry. There is a palpable inequity of supports available to this group of first responders when compared to other common disciplines. The findings support a deeper exploration of TTD's lived experiences on the job, including how best to address their physical and psychological well-being.
The aim of this scoping review was to provide an overview and classification of the studies on workplace health interventions targeted at commercial heavy vehicle drivers. Of the 36 publications included, 28 concerned solely truck drivers, five solely bus drivers, and the remaining three included professionals also from other related fields. The participants were mostly male. Most of the studies (20 publications) examined individual-focused interventions, seven studies focused on organizational interventions, and nine studies addressed both. None of the interventions focused on improving drivers' access to healthcare. More than half of the studies included some form of technological tools. The duration of the interventions was predominantly several months; however, only eight studies reported results after a follow-up period. For future studies, four areas for development were identified. First, collecting and reporting gender-disaggregated data is required to address the unique health needs among female drivers. Second, when using technology, consideration should be given to its usability across the entire workforce and the support needed from human professionals. Third, including systematic follow-up periods would help to understand how long-lasting a behavior change is and what impact it has on health outcomes. Finally, further studies focusing on organizational interventions are especially needed.
Food trucks (FTs) are becoming increasingly popular in Saudi Arabia. However, inadequate food safety practices and limited consumer awareness of foodborne pathogens may increase the risk of foodborne illnesses associated with consumption from FTs. Therefore, we assessed consumer knowledge, attitudes, associations with sociodemographic characteristics, and dietary patterns among FT customers. A cross-sectional study was conducted in the Makkah region, Saudi Arabia, between March to October 2025. An online questionnaire was completed by 500 adults covering sociodemographic characteristics, food safety knowledge, attitudes, pathogen awareness, and dietary intake. Data were analyzed using the independent t-test, one-way analysis of variance, and linear regression. The mean scores for awareness, knowledge, and attitudes were 16.7 ± 3.8, 14.7 ± 3.3, and 30.8 ± 5.3, respectively. Women had considerably higher knowledge and awareness scores than men (p < 0.0001). Significant correlations were found between food safety knowledge and attitude scores (r  =  0.531, p  <  0.001), food safety knowledge and awareness scores (r  =  0.633, p  <  0.001), and attitude and awareness scores (r  =  0.429, p  <  0.001). A trend toward high fruit consumption was observed among participants with high knowledge and awareness scores. These findings highlight the need for targeted consumer education to improve pathogen awareness among FT customers.
[This corrects the article DOI: 10.3389/fvets.2026.1789484.].
This review aims to fill a critical gap-phytosanitation methods for inert surfaces, such as farming equipment, containers, tools, and shoes, to mitigate plant pathogen establishment and expansion. Although a core component to food system security and ecosystem stability, especially for mitigating emerging pathogen impacts, this is one of the least studied disease management tools and often lacks robust science-based practices. We herein synthesize what is known about inert surface phytosanitation practices across diverse microbiological and plant pest systems and highlight opportunities for improving both phytosanitation practices and approaches used for phytosanitation science. Basic frameworks are first established for the types of plant pathogen propagules that are spread on surfaces and dispersal risks posed by key inert surface types. This is followed by a discussion of primary surface phytosanitation methods, including physical, chemical, and heat-based approaches. Case studies of nursery/greenhouse and farm equipment phytosanitation are used to demonstrate both systems-strategies for application of phytosanitation best management practices and methods for developing science-based practices using the hazard analysis for critical control points (HACCP) approach. Opportunities for growth discussed throughout include the use of pathogen-specific analyses and epidemiological modeling to improve phytosanitation science and engineering advancements to make phytosanitation practices more efficient. Taken together, it is hoped that this synthesis can both function as a resource for research/extension practitioners looking to develop and improve phytosanitation practices and provide impetus for innovation.
Accurately estimating the causal effect of human factors on crash severity in mountainous freeways is pivotal for developing effective safety strategies. Although previous studies have investigated human factors, they typically focus on estimating average effects under specific conditions, often conflating statistical correlations with causal relationships. Consequently, the underlying causal mechanisms in freeway crashes remain unclear. To address this limitation, this study proposes a dynamic weighted double machine learning framework that integrates LightGBM and XGBoost models to estimate confounder-outcome and treatment-outcome relationships. By optimizing model weights and using non-human-caused crashes as a control group, the effects of five human factors are isolated through counterfactual reasoning. The heterogeneous treatment effects of human factors on crash severity are quantified, and causal relationships are analyzed across variables such as weather, slope, truck traffic volume, and vehicle type. The results reveal significant heterogeneity in crash severity attributable to human factors compared to non-human factors. Inadequate safety distance often co-occurs with other high-risk conditions, amplifying crash severity. Reversing behavior is particularly sensitive to weather conditions. The causal pathways of distracted or fatigued driving and driving in the wrong lane are influenced by daily truck traffic volume and road slope. Additionally, interactions between slope and vehicle type significantly affect the severity of overloaded crashes. These findings underscore the need for targeted interventions addressing specific human factors in high-risk scenarios. Consequently, enforcement against reversing and overloading on steep slopes with high truck volume should be intensified, and heavy trucks should be restricted to right lanes on high-risk segments.
Waste collection is a critical sector, and maintaining a healthy working environment is essential. This study aimed to (i) characterize waste collectors' exposure to bioaerosols, (ii) examine associations between workday exposure to bioaerosols and serum inflammatory markers, and between week-exposure and self-reported symptoms, and (iii) identify hygiene practices, work tasks, and waste types associated with reported symptoms. In a cross-sectional study, exposure was measured among 56 waste collectors using personal air samplers. Blood samples collected at the end of the workday were analyzed for three inflammatory markers. Participants completed a questionnaire on health symptoms, hygiene practices, and work tasks. Individual week-exposure estimates were derived from exposure measurements among 105 collectors, accounting for season, waste type, and work task. Inflammatory markers indicated low-grade systemic inflammation and were positively associated with workday exposure to anaerobic bacteria. Week-exposure to anaerobic bacteria was associated with increased odds of runny nose and sore throat. Eating in the truck cab was associated with eye symptoms and diarrhea. Use of hand sanitizer was associated with lower odds of nasal symptoms and colds. Cleaning of the truck waste compartment was associated with higher exposure and increased odds of eye and airway symptoms. These findings suggest that anaerobic bacterial exposure, work tasks, and hygiene behaviors may contribute to inflammatory responses and symptoms among waste collectors. The results should be interpreted as hypothesis-generating and support the need for confirmatory intervention studies to evaluate causal relationships and preventive measures related to residual and biowaste collection, truck cleaning, and hygiene practices.
Field data analysis has shown that SUVs and pickup trucks cause more torso injuries than sedans, and the rapid increasing proportion of SUVs among the U.S. vehicle fleet will likely increase the importance of pedestrian torso protection. The objective of this study is to use finite element (FE) vehicle and human body models to investigate effects of vehicle front-end geometry and stiffness characteristics on pedestrian injuries, specifically focusing on SUVs and pickup trucks and pedestrian torso injuries. Front-end geometries of 74 U.S. vehicles, including 41 with hood leading edge (HLE) > 1000 mm and 33 with 750 mm < HLE < 1000 mm, were collected and analyzed using principal component analysis (PCA). The resulting parametric vehicle front-end geometry model was then linked to an FE generic vehicle (GV) model, so that the GV model can be morphed into a wide range of vehicle front-end geometries representing the fleet. Impact simulations using GHBMC F05, M50, and M95 pedestrian models and three detailed vehicle FE models were conducted with the pedestrian perpendicular to the vehicle front-end located at the center of the vehicle. These simulation results were used to calibrate the stiffness values and contact definitions of the hood and hood leading edge components of the morphed GV models. After GV model calibration, several parametric studies were conducted, resulting in a total of 306 vehicle-to-pedestrian crash simulations using 34 morphed GV models with varied front-end geometric and stiffness characteristics and three pedestrian models under three impact velocities (30, 40, and 50 kph). Pedestrian torso injuries were measured by lateral torso deflections at 17 locations across the chest and abdomen regions. Multiple regression was used to test the significance of the variables. PCA results showed that the top three principal components (PCs) captured over 90% of the variation in vehicle front-end geometries, primarily reflecting HLE height/length, HLE roundness, and overall front-end shape. Simulation results suggested that HLE height and impact velocity were the two dominant factors influencing pedestrian torso injury predictions. Torso injury metrics were the highest when the HLE height was equal to or slightly lower than (<150 mm) the pedestrian's mid-sternum height. In addition, increased HLE roundness and a more compliant HLE were associated with reduced pedestrian torso injuries. This study generated a comprehensive set of vehicle-to-pedestrian impact simulation data, enabling a systematic evaluation of how vehicle front-end geometric and stiffness characteristics influence pedestrian torso injuries.
Melasma is an acquired disorder of hypermelanosis that most commonly affects sun-exposed facial skin in women. Extra-facial involvement and occurrence in male patients are uncommon. We present a case of a 66-year-old Hispanic male with asymptomatic, symmetric hyperpigmented patches on the bilateral forearms in the setting of chronic occupational ultraviolet (UV) exposure as a truck driver. Notably, the patient had a history of severe facial burns two years prior to presentation, with complete sparing of facial skin hyperpigmentation. A punch biopsy demonstrated increased basal layer melanin pigmentation with few dermal melanophages and no significant inflammatory infiltrate, consistent with epidermal melasma. The patient was treated with topical azelaic acid and photoprotection counseling but reported minimal improvement, likely related to ongoing UV exposure and occupational constraints. This case highlights an uncommon presentation of extra-facial melasma in a male patient and suggests that prior cutaneous injury may influence melanocytic responsiveness. It also emphasizes the role of chronic UV exposure in disease distribution and persistence.
This study examined the divergence in traffic fatality trends between the United States and Canada from 2007 to 2021. While U.S. fatalities began increasing after 2011, Canada maintained a declining trend. Using data on traffic fatalities and several variables related to travel exposure, demographics, and risk, we analyzed trends for both total and crash-type-specific fatalities. We sought to identify which crash types are primarily responsible for the trends and what risk factors may explain these trends. In both the United States and Canada, several common factors were identified, with the trends being in the opposite direction. These common factors included pedestrian and cyclist fatalities, and alcohol-involved, speeding-related, and truck-involved fatalities. When accounting for exposure by looking at the rate of traffic fatalities per 100 million vehicle miles traveled (MVMT), it appeared that in the United States, a significant amount of the differences in traffic fatalities over time was explained by variations in MVMT, indicating that the level of risk was relatively stable. Conversely, in Canada, the rate of traffic fatalities to MVMT consistently decreased, indicating that other risk factors had decreased. Statistical models confirmed that population and vehicle miles traveled have a positive association with the number of fatalities. Depending on the crash type, gross domestic product per capita and the unemployment rate, variables that influence MVMT, were additional significant exposure-related variables. The models also indicated that part of the difference in fatality trends may be due to Canada's more substantive and common laws related to driver distraction, seat belt use, and the use of speed safety cameras.
Professional drivers worldwide face elevated risks of sleep disturbances and fatigue due to demanding occupational conditions, contributing significantly to road traffic trauma. In Tunisia, where professional drivers are involved in nearly a quarter of all accidents but account for almost a third of fatalities, research in this North African context remains critically limited. This cross-sectional study examined the prevalence and associations of insomnia, fatigue, and risky driving behaviors among 387 professional drivers in Tunisia (mean age 42.3 ± 10.8 years; 99.7% male). Participants completed validated questionnaires including the Insomnia Severity Index (ISI), structured fatigue assessments, and risky driving behavior scales. Results revealed that 34.6% of drivers experienced clinically significant insomnia, with 18.3% reporting moderate-to-severe symptoms. Excessive fatigue while driving was reported by 41.3% of participants, with truck drivers showing the highest prevalence (51.4%). Binary logistic regression analyses demonstrated that insomnia severity (AOR = 2.84, 95% CI: 1.76-4.58, p < 0.001), younger age (<35 years; AOR = 2.12), longer weekly work hours (>60 h; AOR = 1.89), self-employment status (AOR = 1.71), frequent night driving (AOR = 1.68), and short sleep duration (<6 h; AOR = 2.45) were significantly associated with excessive fatigue during driving. Fatigue, in turn, was strongly associated with risky driving behaviors, including drowsy driving (AOR = 7.35, p < 0.001), speeding (AOR = 2.81), mobile phone use (AOR = 2.59), and tailgating (AOR = 2.35). These findings underscore the critical need for multi-level interventions targeting sleep health among Tunisian professional drivers, including workplace schedule optimization, insomnia screening and treatment programs, and strengthened regulatory enforcement of work hour limits. This study provides the first systematic evidence linking insomnia, fatigue, and driving safety in the North African context, contributing essential baseline data for culturally appropriate intervention development.
Children are particularly vulnerable to road traffic injuries (RTIs) leading to morbidity and mortality. Despite the high incidence of pediatric RTIs in Ethiopia, data on the patterns and consequences of pediatric RTIs are limited. To assess the characteristics and ED disposition among pediatric patients (age ≤ 18 years old) with RTI admitted to emergency department of Addis Ababa Burn, Emergency, and Trauma (AaBET) Hospital, Addis Ababa, Ethiopia. A hospital-based cross-sectional study was conducted, focusing on pediatric patients with RTIs who presented it to the emergency department of AaBET Hospital from December 12, 2021, to December 30, 2023, retrospectively. Data were collected using a standardized structured data collection checklist from hospital data records and medical charts. A sample size of 279 pediatric RTI patients was included from registered hospital records. After data cleaning, data were analyzed using SPSS Version 21. Descriptive statistics were used to describe the dependent variables. Out of 279 patients, the median age was thirteen (IQR: 9-17). A total of 54.1% of the patients were male. One hundred and fourteen (40.9%) of those were from age 15-18. Two hundred and eight (74.6%) patients were pedestrians. Forty-eight percent of the patients sustained injury while in transit to work or school. Seventy six (27.2%) came to the hospital with private cars or trucks, while 63 (22.6%) came with an ambulance. One-hundred thirty five (48.4%) of the patients sustained extremity and pelvis injuries, while 41.9% sustained head injuries. Two-hundred fifty-five (91.4%) patients were discharged home from the emergency department. The emergency department mortality was 0.7%. In this study, children from the ages of 15-18 were more affected by RTIs. Pedestrians and while in transit to school or work were more injured. Head and extremity injuries were the predominant injuries that happened to children. Children and schools should be prioritized in targeted road safety initiatives, supported by stricter enforcement of traffic laws near school zones.
Chickens are often transported for a long distance under overcrowded conditions for human consumption, which affects their welfare, health, and even meat quality. The objective of this study was to investigate the interaction effects of transport distance (60 vs. 80 km), stocking density (0.65, 0.86, and 1.30 ft²/bird), and lairage duration (0 vs. 3 hours) on physiological, haemato-biochemical, microbial, carcass, and meat quality characteristics. A total of 324 broilers was used in a 2 × 3 × 2 factorial arrangement, with truck as the experimental unit, and linear mixed models were employed for data analysis. Higher transportation distance and more space allowance were responsible for more body weight loss during transportation (p < 0.05). Significant distance × density interactions were found for white blood cells (WBC), red blood cells (RBC), hemoglobin (Hb), packed cell volume (PCV), corticosterone, and aspartate aminotransferase (AST) (p < 0.05). Birds transported over 80 km had higher WBC, heterophil to lymphocyte ratio (H: L), lactate dehydrogenase (LDH), and glucose compared to those birds transported over 60 km (p < 0.05). The interactions between distance and lairage on triglyceride and AST indicated partial physiological recovery after 3-hour lairage (p < 0.05). The density-lairage interactions for corticosterone, triglyceride, and RBC were significant (p < 0.05). Prolonged transportation distance increased pathogenic bacterial load (log10 CFU/g) and had a negative effect on meat quality characteristics, including cooking loss of thigh muscle and early postmortem pH of breast muscle (p < 0.05). Overall, extended transportation increased physiological stress and microbes, whereas increased space and lairage reduced many of the adverse effects. The study demonstrated the need to improve transportation techniques to enhance broiler welfare and meat quality.
Road traffic crashes remain a leading cause of fatalities worldwide, underscoring the need for accurate data to guide prevention strategies and evidence-based policymaking. However, crash databases often suffer from misclassification, underreporting, and inconsistencies, particularly in alcohol-involved cases, which limits the reliability of safety analyses. This study addresses this issue by identifying and quantifying Misclassified Alcohol-Involved Crashes (MAICs) using a Natural Language Processing (NLP) framework based on the BERT model. The framework analyzed 371,062 crash records from Iowa (2016-2022) and identified 3,895 misclassified alcohol-involved crashes (MAICs) out of 19,177 alcohol-involved cases predicted by the model, corresponding to an overall misclassification rate of 20.35% and a confidence interval of 18.86%-21.85%. To examine the factors contributing to these errors, a mixed-effects Probit Logit regression model was applied, incorporating behavioral, environmental, and roadway attributes. Results indicated that fatal and nighttime crashes were less likely to be misclassified, whereas crashes involving older or younger drivers, heavy trucks, and vulnerable road users showed higher odds of misclassification. A Local Indicators of Spatial Association (LISA) analysis revealed significant county-level clusters of misclassifications, suggesting regional differences in enforcement and reporting practices.
Repetitive, non-concussive head acceleration event (HAE) frequency has not been characterized across track types in professional stock car racing. The objective of this work was to calculate and compare HAE frequency among drivers across track types in the National Association for Stock Car Auto Racing (NASCAR). Head kinematics for 61 drivers were monitored over 39 race weekends at 30 distinct tracks during the 2025 season. Drivers across NASCAR's National series (Truck, Xfinity, and Cup) were instrumented with a custom mouthpiece sensor that tightly couples to the maxillary dentition containing a tri-axial linear accelerometer and gyroscope. A HAE was recorded when a 4 g trigger threshold was exceeded on any axis for at least 3 ms at 1600 Hz. HAEs were identified through filters (time-windowing, wear status) for each driver in each race where they participated and data was collected successfully. Events were visually verified and classified as crash events when associated with caution-causing incidents during active racing; all remaining real events were classified as race events. The number of race events for each driver was then divided by the number of laps completed by that driver to determine HAE rate (HAEs/lap). HAE rates were also calculated on a per-hour and per-race basis using transponder timing data and the number of races where the device was worn and data successfully collected. For this analysis, only feature race HAEs were included due to consistent session type and event data collection. Rates were aggregated to determine summary statistics of mean, median, 95th percentile, and maximum HAE frequencies. Rates were also compared using negative binomial regression to determine rates ratios and 95% confidence intervals. A total of 5,131 HAEs were collected over 239,337 feature racing laps. The lowest number of races (n = 14), laps completed (n = 14,752), and driver-races (n = 195) occurred at road courses with the greatest occurring at intermediate tracks (n = 44, n = 132,419, n = 621, respectively). Road courses resulted in significantly greater rates (p < 0.05) and the highest mean, median, 95th percentile, and maximum rates compared to all track types, where per-lap rates were 0.1246, 0.0733, 0.4264, and 0.5565 HAEs/lap. Comparatively, superspeedways had the lowest mean, median, and maximum rates at 0.0046, 0.0027, and 0.0222 HAEs/lap. The lowest 95%ile HAEs/lap occurred at intermediate tracks (0.0172). Instrumented mouthpieces were used to quantify HAE frequency across track types. Calculating HAE frequency on a per lap basis allows for comparisons of drivers across track types. Road courses had the greatest, mean, median, 95%ile, and maximum HAE rates. This study provides empirical evidence that warrants further investigation into road courses, which may elucidate factors contributing to increased rates. These findings additionally provide a framework for assessing race HAE rates that could provide insights to inform evidence-based decisions to improve driver safety.
Harmful Algal Blooms (HABs) are pervasive in freshwater and marine waters requiring advances in monitoring, prevention and control of active blooms. Prevention through interception of nutrient runoff that feed HABs is critical to reducing future impacts. This research provides a logical convergence of complementary goals of mitigating the severity of HABs and increasing beneficial use of dredged sediment conveniently sourced from Confined Disposal Facilities (CDFs). This work innovates use of additive manufacturing (AM), or 3D printing, to generate porous, geometrically complex sediment structures to adsorb and intercept nutrients in runoff water prior to discharge into surface water. While this technology application is widely applicable, proof-of-principle of nutrient removal capability is demonstrated using a 3D printed dredged sediment mound that was strategically placed on a 3 by 3-foot physical landscape model that was also completely 3D printed. The sediment mound structure was specifically printed into parallel roadways forming channels to increase preferential infiltration of run-off water into the otherwise clayey sediment. Nutrients were measured before and after pumped runoff water passed through either amended (biochar, commercial resins) or unamended dredged sediment structures and demonstrated that the unamended marine-sourced dredged sediment had sufficient capacity to almost immediately reduce concentrations of phosphate by 79 to 98% and nitrate by 93 to 99% from runoff discharge. This concept may be scaled using hoppers, excavators and trucks to move sediment from nearby CDFs to a runoff site for field demonstration and application.
This study investigates the determinants of vulnerable road user (VRU) crash severity by accounting for unobserved heterogeneity both across and within crash subpopulations. Conventional single-model approaches assume homogeneous effects across all crashes, potentially masking context-dependent severity mechanisms. Crash data for 15,578 pedestrian and 11,433 bicyclist collisions occurring at or near intersections in 20 California cities (2016-2025) were extracted from the Statewide Integrated Traffic Records System (SWITRS). A two-stage analytical framework was employed. First, latent class analysis identified three distinct crash typologies for each VRU mode based on movement patterns, lighting, weather, and collision factors. Second, mixed logit (MXL) models were estimated for each latent class to capture within-cluster heterogeneity through random parameters. Pseudo-elasticity analysis quantified the practical magnitude of variable effects. Temporal stability was assessed by estimating separate models across pre-COVID, during-COVID, and post-COVID periods. Truck involvement, dark conditions without streetlights, and state highway location consistently elevated severe outcome odds across all clusters for both VRU types, while VRU age 65+ shifted injury distributions toward moderate rather than the most severe outcomes. Critically, several factors exhibited context-dependent effects. VRU fault increased severity when drivers traveled straight, but decreased severity in turning-driver crashes for bicyclists, indicating fundamentally different causal mechanisms. State highway effects ranged from the strongest fatal predictor in straight-driver pedestrian crashes to non-significant in other configurations. Different random parameters were identified across clusters, confirming that unobserved heterogeneity operates through distinct mechanisms in different crash contexts. Crash severity determinants are both universally important and context-dependent, with the same variable capable of opposing effects across crash configurations. These findings demonstrate that aggregate models pooling heterogeneous crash types obscure critical variation and support the adoption of context-sensitive approaches to crash modeling.