Search Results (13)

This review systematically synthesizes recent advances in road snow and ice removal equipment, with emphasis on operating mechanisms, applicable conditions, key parameters, and development trends. Mechanical ice-breaking and snow removal equipment—including rolling, rotary-cutting, impact, snowplow, and rotary brush systems—is evaluated in terms of operating principles and engineering applicability. The energy input modes and dominant performance factors of hot-air, steam, microwave, and laser deicing technologies are then summarized. In addition, the structural configurations and functional coordination of mechanically integrated and thermal–mechanical snow removal vehicles are examined. These technologies differ substantially in ice-breaking capability, operating speed, energy consumption, and risk of pavement damage. Current research is further limited by inconsistent performance metrics, insufficient validation under field operating conditions, and inadequate parameter matching among functional units. Future studies should therefore emphasize snow and ice condition sensing, adaptive regulation of operating parameters, and coordinated control of multiple functional units. This review provides a systematic basis for equipment selection, performance evaluation, and the design of integrated road snow and ice removal systems. Full article

Snow removal vehicles operate under severe working conditions, and the snowplow mounting frame is a critical structural component responsible for transmitting loads generated during snow-removal operations. To improve material utilization and reduce structural weight without compromising mechanical performance, a lightweight design methodology based on topology optimization was developed. The primary design objective was to achieve at least a 16% reduction in structural mass while maintaining acceptable stress, strain, deformation, and durability performance. First, a three-dimensional model of the mounting frame assembly was established, and finite element analysis was conducted using ANSYS under representative loading conditions. Topology optimization based on compliance minimization with a mass constraint was then performed to identify structurally inefficient regions and generate an optimized material distribution. Based on the optimization results, the mounting frame was reconstructed into a practical and manufacturable CAD model and subsequently re-evaluated through finite element analysis and fatigue assessment. The mass of the mounting frame was successfully reduced from 177.52 kg to 137.77 kg, corresponding to a weight reduction of 22.39%, significantly exceeding the initial design target. Despite this substantial reduction in weight, the maximum stress, strain, and deformation remained within allowable design limits. Furthermore, fatigue analysis predicted no fatigue failure within 1 × 10⁶ loading cycles, while the minimum fatigue safety factor remained greater than unity, confirming the durability and reliability of the redesigned structure. The results demonstrate that topology optimization provides an effective approach for improving material utilization, reducing structural weight, and enhancing the overall structural efficiency of snow-removal equipment. The successful reconstruction of the optimized topology into a manufacturable design further highlights the practical industrial applicability of the proposed methodology. Full article

Flowable composites improve adaptability at the gingival margin but may affect mechanical properties. This study tested the surface hardness of proximal restorations as indicator of depth-of-cure and mechanical properties. Typodont teeth with 4 mm deep disto-occlusal preparations were (a) restored with three flowable composites in 4 mm bulk, and (b) restored with a thin layer of a flowable at the gingival margin under a universal composite. For the latter, two techniques were tested: ‘pre-cure’ and ‘snowplow’. In the pre-cure technique, the flowables were cured separately; in the snowplow technique, they were cured together with the universal composite. The universal composite placed in two 2 mm increments was the control. After 24 h, the Vickers hardness of the proximal restorations was measured every 0.5 mm from occlusal to gingival. The results were statistically analyzed using ANOVA and post hoc tests (α = 0.05). The sample size was 10/group. Bulk-filled restorations having undergone 40 s of light curing were significantly harder than those cured for 20 s. The pre-cure technique decreased hardness at depths of 3 mm and greater. The snowplow technique also led to significantly lower hardness at 4 mm, but less reductions at the 3.0 and 3.5 mm depths. The fiber-reinforced flowable composite increased the overall hardness of the restorations. In conclusion, using a flowable composite in a thin layer at the gingival margin to improve adaptation affected the hardness of the restoration. The snowplow technique reduced the softening effect associated with flowable composites compared to the pre-cure technique. Full article

For effective winter road management in snow-prone regions, timely snow removal that reflects weather and traffic conditions is required. In Akita City, Japan, city hall staff measure snow depth and dispatch contracted snow removal crews only when a predefined threshold is exceeded. Consequently, dispatch decisions depend heavily on staff experience. This study demonstrates objective, experience-independent dispatching based on predicting the number of snowplow dozers in operation, thereby reducing the municipal decision burden and improving contractor efficiency. The target variable is highly imbalanced, with long non-operational periods and wide variations in the number of deployed units during snowfall events. When trained directly on such data, models tend to regress toward near-median values and face difficulty capturing operational dynamics. To address this issue, we propose a two-stage framework: firstly, a classifier predicts whether snow removal operations will occur; secondly, a regressor estimates the number of operating dozers based on the operation. We further integrate multi-year datasets to enhance generalization across diverse snow conditions. Experiments showed that the proposed approach achieved an AUPRC of 0.84 for operation occurrence and an RMSE of 1.85 for dozer-count estimation, outperforming models trained on a single year. Full article

Background/Objectives: Postoperative sensitivity remains a common challenge following direct composite restorations, especially in Class II cavities with deep proximal boxes. The snow-plow and resin-coating techniques have been proposed to improve marginal adaptation and reduce postoperative discomfort; however, comparative clinical data remain limited. This prospective, split-mouth, quasi-experimental study aimed to compare postoperative pain associated with Class II restorations placed using either the snow-plow or resin-coating technique. Methods: This prospective, split-mouth study followed 83 adult patients (aged 18–45 years) who received bilateral Class II composite restorations for one week. The study received ethical approval. Each participant received one restoration using the snow-plow technique and another using the resin-coating approach. Pain intensity was evaluated using a 10-point visual analog scale (VAS) at baseline, 24-h, 72-h, and 1-week postoperatively. Analyses included Wilcoxon signed-rank, Friedman, Chi-square, McNemar, and two-way repeated-measures ANOVA tests. Results: Pain intensity peaked at 24-h for both techniques and declined significantly by 72-h and 1 week (p < 0.001). The snow-plow technique showed slightly lower mean pain scores at 24 and 72 h (p = 0.026 and p = 0.004, respectively), though categorical analyses revealed no significant difference in pain-free or minimal-pain proportions at any interval (p > 0.05). Both techniques showed significant within-group reductions in pain over time (p < 0.001). Conclusions: Both restorative approaches demonstrated similar postoperative pain trajectories, with substantial improvement by one week. While minor differences in early mean pain intensity were observed, these were not clinically significant. The findings suggest that either technique can be effectively employed to achieve satisfactory postoperative comfort when modern adhesive protocols are applied. Clinicians can therefore select either technique based on preference and clinical circumstances, with the expectation of comparable short-term postoperative comfort outcomes. Full article

(1) Background: Alpine skiing, with its long history, has experienced numerous innovations and developments on all levels ranging from technology to fashion over the past 120 years. However, teaching approaches for beginners remained quite consistent for many decades and are mainly grounded in experience. The One-Ski-Method (OSM) is an alternative approach to the predominant snowplow (SP) method with the strategy to initially experience and acquire the elementary positions and actions on one ski in order to subsequently transfer these to two skis. The aim of the study was to compare the effects of the SP and the OSM by assessing the position of the ski via load distribution sensors. (2) Methods: A total of 33 participants were groupwise randomly assigned to the two methods and tested via load insoles on the first and the fifth day on a moderate slope for six turns. Between the two measurements, the groups were instructed according to the SP or the OSM methods, respectively. The data were analyzed via Matlab and SPSS. (3) Results: The OSM group showed a significantly greater forefoot load than the SP group (p = 0.029). The SP group developed a greater rearfoot loading from pre- to post testing. (4) Conclusions: The findings make it perceivable that OSM learners acquire a beneficial specific position on the ski due to the exercises of the OSM. Full article

Good visibility of lane markings is important for all road users, particularly autonomous vehicles. In general, nighttime retroreflectivity is one of the most challenging marking visibility characteristics for agencies to monitor and maintain, particularly in cold weather climates where agency snowplows remove retroreflective material during winter operations. Traditional surface-applied paint and glass beads typically only last one season in cold weather climates with routine snowplow activity. Recently, transportation agencies in cold weather climates have begun deploying improved recessed, durable pavement markings that can last several years and have very high retroreflective properties. Several dozen installations may occur in a state in any calendar year, presenting a challenge for states that need to program annual repainting of traditional waterborne paint lines, but not paint over the much more costly durable markings. This study reports on the utilization of mobile mapping LiDAR systems to classify and evaluate pavement markings along a 73-mile section of westbound I-74 in Indiana. LiDAR intensity data can be used to classify pavement markings as either tape or non-tape and then identify areas of tape markings that need maintenance. RGB images collected during LiDAR intensity data collection were used to validate the LiDAR classification. These techniques can be used by agencies to develop accurate pavement marking inventories to ensure that only painted lines (or segments with missing tape) are repainted during annual maintenance. Repeated tests can also track the marking intensity over time, allowing agencies to better understand material lifecycles. Full article

Efforts to enhance quality control (QC) practices in chip seal construction have predominantly relied on single surface friction metrics such as mean profile depth (MPD) or friction number. These metrics assess chip seal quality by targeting issues such as aggregate loss or excessive bleeding, which may yield low friction numbers or texture depths. However, aggregate loss, particularly due to snowplow operations, does not always result in slippery conditions and may lead to uneven surfaces. The correlation between higher MPD or friction number and superior chip seal quality is not straightforward. This research introduces an innovative machine learning-based approach to enhance chip seal QC. Using a hybrid DBSCAN-Isolation Forest model, anomaly detection was conducted on a dataset comprising 183,794 20 m MPD measurements from actual chip seal projects across six districts in Indiana. This resulted in typical 20 m segment MPD ranges of [0.9 mm, 1.9 mm], [0.6 mm, 2.1 mm], [0.3 mm, 1.3 mm], [1.0 mm, 1.7 mm], [0.6 mm, 1.9 mm], and [1.0 mm, 2.3 mm] for the respective six districts in Indiana. A two-step QC procedure tailored for chip seal evaluation was proposed. The first step calculated outlier percentages across 1-mile segments, with an established limit of 25% outlier segments per wheel track. The second step assessed unqualified rates across projects, setting a threshold of 50% for unqualified 1-mile wheel track segments. Through validation analysis of four chip seal projects, both field inspection and friction measurements closely aligned with the proposed methodology’s results. The methodology presented establishes a foundational QC standard for chip seal projects, enhancing both acceptance efficiency and safety by using a quantitative method and minimizing the extended presence of practitioners on roadways. Full article

Wheeled machines, such as agricultural tractors, snowplows, and wheeled mobile robots, usually work on icy or snow-covered roads. Therefore, it is very important to study the driving and slip resistance of the tires of these machines. In this paper, we investigate the driving behavior of tires on snow-covered terrain by means of numerical simulations. A high-fidelity snow-covered road model is established, and smoothed particle hydrodynamics (SPH) and the finite element method (FEM) are employed to account for the behaviors of the snow layers and the pavement, respectively. We use the node-to-surface algorithm for the contact interactions between the snow and the pavement. The SPH parameters for the snow are calibrated by means of a triaxial compression experiment. A simplified tire model is established as well, using the FEM, and the effectiveness of the model is demonstrated via comparisons with the experimental data in terms of stiffness. Finally, the tire driving performance on the snow-covered road is simulated, and the influence of the tire surface configuration, external load, inflation pressure, and snowpack compression on the tire traction behaviors is systematically investigated. Full article

During the winter season, snowplowing has a significant effect on road users as it is critical to winter road maintenance and operations. The main goal of this study is to generate optimal routes for snowplowing trucks for efficient road maintenance. In addition to the conventional problem of reducing travel time and distance, this study also incorporates actual operational constraints, such as minimum maintenance standards and driver safety, to improve the overall efficiency of operations. To achieve the objectives, we first implemented the Chinese Postman Problem (CPP) to create Euler circuits from the initial routes and then identified the shortest paths by applying Dijkstra’s algorithm. Then, the Tabu search algorithm was chosen as a metaheuristic algorithm for the optimization process that finds near-optimal solutions by considering operational constraints for snowplow routes. Unsafe turning conditions and minimum maintenance standards were taken into account in the objective function defined for the optimization process. In simulations, the route obtained by our approach was compared to one with the application of CPP only in terms of travel distance, time, turning conditions, and road maintenance priority. Full article

There are over four million miles of roads in the United States, and the prioritization of locations to perform maintenance activities typically relies on human inspection or semi-automated dedicated vehicles. Pavement markings are used to delineate the boundaries of the lane the vehicle is driving within. These markings are also used by original equipment manufacturers (OEM) for implementing advanced safety features such as lane keep assist (LKA) and eventually autonomous operation. However, pavement markings deteriorate over time due to the fact of weather and wear from tires and snowplow operations. Furthermore, their performance varies depending upon lighting (day/night) as well as surface conditions (wet/dry). This paper presents a case study in Indiana where over 5000 miles of interstate were driven and LKA was used to classify pavement markings. Longitudinal comparisons between 2020 and 2021 showed that the percentage of lanes with both lines detected increased from 80.2% to 92.3%. This information can be used for various applications such as developing or updating standards for pavement marking materials (infrastructure), quantifying performance measures that can be used by automotive OEMs to warn drivers of potential problems with identifying pavement markings, and prioritizing agency pavement marking maintenance activities. Full article

In alpine skiing, four commonly used turning styles are snowplow, snowplow-steering, drifting and carving. They differ significantly in speed, directional control and difficulty to execute. While they are visually distinguishable, data-driven classification is underexplored. The aim of this work is to classify alpine skiing styles based on a global navigation satellite system (GNSS) and inertial measurement units (IMU). Data of 2000 turns of 20 advanced or expert skiers were collected with two IMU sensors on the upper cuff of each ski boot and a mobile phone with GNSS. After feature extraction and feature selection, turn style classification was applied separately for parallel (drifted or carved) and non-parallel (snowplow or snowplow-steering) turns. The most important features for style classification were identified via recursive feature elimination. Three different classification methods were then tested and compared: Decision trees, random forests and gradient boosted decision trees. Classification accuracies were lowest for the decision tree and similar for the random forests and gradient boosted classification trees, which both achieved accuracies of more than 93% in the parallel classification task and 88% in the non-parallel case. While the accuracy might be improved by considering slope and weather conditions, these first results suggest that IMU data can classify alpine skiing styles reasonably well. Full article

A recent body of research in fatigue management indicates that other factors, including in-cab and external equipment, contribute to operator fatigue. The goal of this project was to identify winter road maintenance equipment (in-cab and external) that may increase or mitigate snowplow operator fatigue. To accomplish this goal, questionnaires from 2011 snowplow operators were collected from 23 states in the U.S. Results confirmed previous research that fatigue is prevalent in winter road maintenance operations. Winter road maintenance equipment that produced excessive vibrations, noise, reduced visibility, and complex task demands were found to increase snowplow operators’ self-reported fatigue. Similarly, equipment that reduced vibrations and external noise, improved visibility, and limited secondary tasks were found to reduce snowplow operator’s self-reported fatigue. Based on the questionnaire responses and the feasibility of implementation, the following equipment may help to mitigate or prevent snowplow operator fatigue: dimmable interior lighting, LED bulbs for exterior lighting, dimmable warning lights, a CD player or satellite radio in each vehicle, heated windshield, snow deflectors, narrow-beam auxiliary lighting, and more ergonomically designed seats with vibration dampening/air-ride technology. Full article