Truck Impact Research Articles

Investigating crashworthiness of W-Beam guardrail crash barriers

This study presents the evaluation of safety performance of the blocked-out W-Beam guardrail crash barrier system designed as per the ‘Guidelines for traffic safety barriers’ published by Indian Road Congress (IRC:119-2015). A finite element model of the W-Beam guardrail was developed in Hyper-Mesh and the simulation of the crash analysis was performed in LS-Dyna. Results from the simulation were used to study the compliance of the barrier with the test acceptance criteria of the NCHRP 350 report for containment level TL-3 as mentioned in the IRC: 119-2015. Finite element models of 820c passenger car and 2000p pickup truck developed by NCAC were imported to the guardrail model for crash simulation according to the test designation 3-10 and 3-11. As per the acceptance criteria of the NCHRP report 350 for containment level TL-3, the obtained simulation results were examined to verify the compliance and performance of the guardrail. It was concluded that the crash barrier was compliant with test 3-10 but not with 3-11. Further, simulations for TL-1 (test 1-11) were also conducted since the barrier failed to meet the NCHRP criteria for pickup truck impacting at 100 km/h. It was found that the barrier fulfilled the criteria for pickup truck impact with 50 km/h velocity.

Performance impact of autonomous trucks on flexible pavements: an evaluation framework and case studies

ABSTRACT The emerging technology of Autonomous Trucks (ATs) will significantly impact the transportation sector. Unique traffic characteristics of ATs, such as lane choice and lateral positioning, could intensify the potential risk of aggravated distress development on flexible pavements. In response, the present work proposes a framework to evaluate this impact, focusing on critical factors like wheel wander, load spectra, and AT road-sharing percentages. We utilized this framework to assess AT's effect on Texas' flexible pavements and conducted a parametric analysis, exploring their response to AT implementation and identifying the significance of some key parameters in different pavement designs. The key findings offer insights into how AT implementation could potentially reduce the lifespan of flexible pavements based on existing data. These insights will prove beneficial in designing future pavements that are better suited to accommodate the rising influx of autonomous trucks. Though some AT attributes are yet undetermined due to their emergent nature, our robust framework will accommodate new data when it is available, serving as a continuously improving evaluation tool.

Nonlinear Dynamic Assessment of a Steel Frame Structure Subjected to Truck Collision

The progressive collapse of structures subjected to a truck collision with ground floor columns is numerically investigated in this paper. For this purpose, a four-story steel building with a dual system (including an intermediate steel moment frame, with a special concentric steel bracing system in the longitudinal (x) direction, and an intermediate steel moment frame in the transversal (y) direction) is considered. The structure, which was designed according to AISC, ASCE7 and 2800 Iranian seismic standard guidelines, is located in seismic-prone area and subjected to eight different truck collision scenarios. The nonlinear dynamic analyses carried out in ABAQUS on a three-dimensional finite element (FE) numerical model include variations in collision features (i.e., mass and speed of the truck, the height of collision point), and are used to support the analysis of expected damage. The presented results confirm that increasing the truck mass and speed increases damage entity for the column and structure. Several influencing parameters are involved in damage location and progressive evolution. The height of the collision point from the ground also significantly affects the magnitude of structural damage, especially in terms of stress peaks in the panel zones for the target column. Finally, the perimeter columns are more vulnerable to impact than corner columns, in structures with dual system as with the examined four-story building. The presence of a bracing system parallel to the impacting vehicle can in fact reduce the deformation—and thus the expected damage—of the adjacent target column. Most importantly, it is shown that the numerically reproduced collision scenarios (and the associated damage configurations) based on truck impact are significantly more severe than those artificially created based on the conventional column removal method (i.e., alternate path (AP) analysis approach), which confirms the importance of more sophisticated numerical calculation procedures to investigate and assess the progressive collapse of structures.

Platoon Cooperation Across Carriers: From System Architecture to Coordination

Truck platooning is a well-studied technology that has the potential to reduce both the environmental impact and operational costs of trucks. The technology has matured over the last 20 years, and the commercial rollout of platooning is approaching. Cooperation across carriers is essential for the viability of platooning; otherwise, many platooning opportunities are lost. We first present a cross-carrier platooning system architecture in which many carriers cooperate in forming platoons through a platoon-hailing service. Then, we present a cross-carrier platoon coordination approach in which each carrier optimizes its platooning plans according to the predicted plans of other carriers. A profit-sharing mechanism to even out the platooning profit in each platoon is embedded in the platoon coordination approach. Finally, a simulation study over the Swedish road network is performed to evaluate the potential of platooning under realistic conditions. The simulation study shows that the energy consumption of trucks in Sweden can be reduced by 5.4% due to platooning and that cooperation across carriers is essential to achieve significant platooning benefits.

Evaluating the impact of overweight trucks on rigid pavement performance using AASHTOWare pavement ME design

ABSTRACT The purpose of this study is to evaluate the impact of overweight vehicles on pavement performance over its design life, with Jointed Plain Concrete Pavements (JPCPs) particularly considered for analysis. The Long-Term Pavement Performance database was used to provide information on pavement construction, age, overall structure, specific traffic inputs, and recorded historical pavement performance. AASHTOWare Pavement ME Design (PMED) was used to analyze data extracted from LTPP based on legislation by the Federal Highway Administration (FHWA) regulating gross vehicle weight (GVW) and single and tandem axle weights of overweight trucks (OWTs) to estimate pavement performance and service life. The overall findings indicated that although increasing overweight by 20% on single or tandem axles could considerably reduce pavement service life by up to 20% in the various scenarios examined in this study, OWT exceeding the GVW limit legally-allowed by FHWA could damage pavement more than OWT exceeding axle weight limits.

Residual Deformation-Based Performance Evaluation Method for CFST Piers Subjected to Vehicle Collision

Concrete-filled steel tubular (CFST) piers have been applied in bridge structures due to their high bearing capacity, good ductility, and light weight. During their service life, CFST piers may suffer vehicle collision. Nevertheless, there is still a lack of a performance evaluation method for CFST piers subjected to vehicle impact. Therefore, this paper presents a residual deformation-based method to evaluate the performance of CFST piers under truck impact. Before that, a numerical model was developed to simulate responses of CFST piers under truck collision and validated by reported impact tests. Then, the performance levels of 6- and 12-m high CFST piers under 20 and 40 ton and 60, 100, and 140 km/h truck collisions were numerically investigated. Afterwards, a residual deformation-based performance evaluation method was proposed based on the numerical investigations. In this method, the ratio of the residual lateral deflection at the mid-height to half of the pier height was first selected as the evaluation index. Then, threshold values of the evaluation index at different performance levels were determined. Finally, an analytical model for the evaluation index was developed. Comparisons indicate that the analytical performance levels are in good agreement with the numerical results. The proposed residual deformation-based performance evaluation method can be used for design and accident analysis of CFST piers subjected to truck collision.

Impact of electric trucks in GHG inventory – A Uruguayan scenario study

Impact of electric trucks in GHG inventory – A Uruguayan scenario study

Dynamic response of precast segmental bridge columns under heavy truck impact

Dynamic response of precast segmental bridge columns under heavy truck impact

Lifecycle climate impact and primary energy use of electric and biofuel cargo trucks

AbstractHeavy trucks contribute significantly to climate change, and in 2020 were responsible for 7% of total Swedish GHG emissions and 5% of total global CO2emissions. Here we study the full lifecycle of cargo trucks powered by different energy pathways, comparing their biomass feedstock use, primary energy use, net biogenic and fossil CO2emission and cumulative radiative forcing. We analyse battery electric trucks with bioelectricity from stand‐alone or combined heat and power (CHP) plants, and pathways where bioelectricity is integrated with wind and solar electricity. We analyse trucks operated on fossil diesel fuel and on dimethyl ether (DME). All energy pathways are analysed with and without carbon capture and storage (CCS). Bioelectricity and DME are produced from forest harvest residues. Forest biomass is a limited resource, so in a scenario analysis we allocate a fixed amount of biomass to power Swedish truck transport. Battery lifespan and chemistry, the technology level of energy supply, and the biomass source and transport distance are all varied to understand how sensitive the results are to these parameters. We find that pathways using electricity to power battery electric trucks have much lower climate impacts and primary energy use, compared to diesel‐ and DME‐based pathways. The pathways using bioelectricity with CCS result in negative emissions leading to global cooling of the earth. The pathways using diesel and DME have significant and very similar climate impact, even with CCS. The robust results show that truck electrification and increased renewable electricity production is a much better strategy to reduce the climate impact of cargo transport than the adoption of DME trucks, and much more primary energy efficient. This climate impact analysis includes all fossil and net biogenic CO2emissions as well as the timing of these emissions. Considering only fossil emissions is incomplete and could be misleading.

Investigating the effect of truck intensity on sustainability conditions of a motorway

The significant increase in freight transport during an after the COVID-19 era, is leading to a continuous increase in the number of trucks and their proportion in traffic conditions. The objective of the present study is to quantify the impact of trucks on traffic and environmental conditions of a motorway. To achieve this objective, traffic data from Nea Odos Motorway were used for a period of two months in 2021. Within the analysis framework, micro-simulation was used in order to examine impacts mainly on traffic, environment and energy efficiency on network level for different penetration rate scenarios of trucks. Results indicate several insights for the network due to different penetration rates of truks confirming that traffic and environmental conditions are largely affected by freight transport and providing stakeholders and policy makers with important conclusions.

Pricing of the Bus-Truck Co-Delivery Mode of Last Mile Delivery Considering Social Welfare Maximization

In order to solve the problems of low delivery efficiency and high cost at the end of express delivery, and the impact of express trucks on urban road traffic, the co-delivery mode of trucks and buses is proposed. In this mode, without affecting the normal operation of the bus, it uses the idle resources of the bus to cooperate with the trucks to complete the delivery. The express company pays the bus delivery service fee to the bus operator, so as to improve the revenue of the bus operator. At the same time, the delivery efficiency can be improved, the express delivery cost can be reduced, and the impact of express trucks on urban traffic can be lower. A two-layer optimization model is constructed to solve the bus delivery service pricing and express space-time path selection scheme under the co-delivery mode. An example analysis is carried out through the actual bus routes and express delivery demand in Dalian. The results show that the co-delivery mode can provide consumers with more efficient services, reduce costs for express companies, provide additional revenue for bus operators, and improve social welfare. Unless the timeliness of delivery is extremely considered, the measure of using the co-delivery mode is better than the measure of relaxing restrictions on express delivery vehicles.

Experimental Investigation of the Forklift Truck Impact on CFS Pallet Racks

Background: Storage pallet racks are commonly formed by Cold-Formed-Steel (CFS) members and are used worldwide to store goods on pallets. The main racking system is denoted as “selective pallet racking”. This racking system is one pallet deep and is separated by aisles, allowing for each pallet, stored on horizontal beams, to be always accessible. Steel racking systems are frequently subjected to accidental impact forces from operating forklift trucks. If international racking design codes provide an arbitrary value of impact force to design members, several impacts can produce damages, which can lead to system failure, highlighting the fundamental role played by monitoring. Methods: Results of an experimental campaign on a full-size selective rack are presented. The investigated rack is subjected to the impact of a forklift truck and hammer test at different points. The propagation of the acceleration among adjacent bracing frames is investigated with the magnitude of the recorded strains in structural members. Results: Results highlight that an accelerometer every two spans can establish whether the monitored racking system is accidentally hit. Compressed diagonal and tensile diagonal work in parallel. Only one diagonal brace, every two spans, can be monitored through a strain gauge to establish the forklift truck impact point and estimate the stress distribution on adjacent members. Conclusion: The study suggests an optimization in the number, type and position of accelerometers and strain gauges in monitoring racking systems to identify forklift truck impact and its effects.

Enhanced Road Network to Reduce the Effect of (External – External) Freight Trips on Traffic Flow

The transportation system is often described as the lifeblood of modern society. Roads constitute a fundamental part of this system for both passenger and freight transports, a well-functioning freight transportation system is an essential element in any successful economy. Hilla is one of the most densely populated cities in Iraq. The road network in Hilla city is under additional load due to (external - external) trips, especially freight trips by trucks passing through the city's main entrances to cross into neighboring districts and provinces. This is due to the city's strategic location, which connects Baghdad with the southern provinces, making it an important transit route. The objective of this research is to study a proposal for modifying and developing the road network in the city of Hilla by adding new roads to the current network in order to reduce the negative impact of freight trucks passing through the city, especially (external - external) trips, by using Trans CAD and ArcGIS software network analysis. The result of network analysis shows that the suggested roads will reduce the total (travel time and distance) for the same origin and destination points by 9%, and 30%, compared with the current distance and time, respectively, while improving the level of service from D to C at peak hours for freight vehicles. Doi: 10.28991/CEJ-2022-08-11-015 Full Text: PDF

Quarterly Instability Analysis of Injury Severities in Truck Crashes

The impact of trucks on road traffic safety has been extensively studied, but the factors influencing truck crash injury severity have not yet been examined from the quarterly perspective. Crash data for Shandong Province in China for 10 years (2012–2021) were reviewed to investigate the transferability of the determinants of the severity of truck crash injuries in four quarters. Three injury severity levels were considered and a random parameters logit model (RPL) considering the heterogeneity of means and variances was constructed to assess the factors affecting the severity of crash injury. The significant variables were explored from the influencing factors of driver, vehicle, crash type, road, environment, and temporal characteristics. A likelihood ratio test was employed to assess the transferability of the crash model over four quarters, and we used marginal effects to analyze the stability of the influencing factors. The results indicated that there was instability among the four quarterly variables that had to be modeled separately. There were also some variables, such as heavy vehicle and multiple-vehicle crashes, that simultaneously affected the severity of truck crash injuries across the four quarters, but the degree of impact was different. The results could enable engineers and policy makers to better formulate management rules and propose appropriate measures according to quarterly changes.

Impact of trucks registered in other provinces on ETC differentiated charging in provincial expressway network

To evaluate the effect of policy on province-wide toll discount for electronic toll collection (ETC) trucks, and to clarify the influence of trucks registered in other provinces on the toll discount flowed back to the local enterprises, we use structured query language server (SQL Server) database technology to process the toll collection data on expressway network, and propose an algorithm of recovery rate for the explanatory variables of toll preference, and verify the feasibility of the algorithm is by a case study. The results show that the recovery rate of the study case is 43.38% when there is an 85% discount on ETC truck toll in 2019, and 52.77% of the 56.62% toll discount outflowed from the case studied is generated by the trucks registered in other provinces according to a conservative estimate. Among them, the proportion of the toll discount of trucks registered in other provinces with 6 axles accounts for 77.29%, which is the root of toll discount loss. Although the traffic number across the province is not large, the toll discount is rather large owing to the long distance and heavy load. The recovery or loss of toll discount concentrates in the trucks with 2 axles, 4 axles and 6 axles, and trucks with 6 axles accounting for the largest proportion. This paper provides a reliable analysis basis for the accuracy of the differential charging policy on expressway, and promotes the rapid development of transportation economy.

Modeling impacts of the tunnel section on the mixed traffic flow: A case study of Jiaodong’ao Tunnel in China

Modeling impacts of the tunnel section on the mixed traffic flow would be a challenge. It needs to figure out the traffic regulations of the tunnel section that vehicles must comply with. Also it requires depicting the different driving behaviors of cars and trucks when they run into the tunnel. To deal with these problems, we propose a two-lane cellular automaton (CA) traffic model with a tunnel section based on the single-lane CA model proposed by Guzmán (LAI-E model). The asymmetric lane-changing rules with right-lane preference are adopted for trucks, and the symmetrical lane-changing rules are adopted for cars. Especially, the impact of trucks on cars’ driving pattern is taken into account. The drivers’ individual character difference, i.e., cautious and radical, are also considered. The results indicate that the time series of traffic flow, vehicles’ speed in different tunnel sections and trucks’ proportions obtained from the numerical simulation are in good agreement with those obtained from the measured data. The phenomena of the speed fluctuation at the entrance and the exit of the tunnel are reproduced. Besides, the driving pattern of cars’ keeping away from trucks is captured from the spatial–temporal diagrams, and the unbalanced utilization of two lanes, i.e., large usage in the left lane and small usage in the right lane, is revealed. The further simulation indicates that the unbalanced utilization of two lanes will be improved if the trucks’ blocking influence could be neglected. The results will provide a theoretical reference for the optimization of traffic flow in the highway tunnel sections.

EXPERIMENTAL DETERMINATION OF THE INFLUENCE OF HEAVY CARGO VEHICLES ON THE ROAD SURFACE OF THE HIGHWAYS OF THE KYRGYZ REPUBLIC

The article examines the impact of trucks on the road surface with loads close to the norm.

Impact of Autonomous and Human-Driven Trucks on Flexible Pavement Design

Truck platooning with autonomous and connected vehicles has several advantages compared with traditional trucking. Platooning improves overall road safety and reduces fuel consumption by up to 15%. This is a result of the advanced control systems and high steering accuracy of autonomous vehicles. These advanced control systems present an opportunity to pavement design engineers, as the lateral positions of the vehicles could be altered to create less damaging loading scenarios. This study introduces an expected response framework to quantify the impact of lateral position on pavement performance. Using the expected response framework, any mixture of human-driven and autonomous vehicles can be analyzed by characterizing lane position as a mixture probability distribution instead of point loads. Pavement damage can subsequently be computed by using the expectation of the responses. This approach requires little computational effort and is easily incorporated in any mechanistic–empirical design or optimization framework. The approach is illustrated by analyzing four flexible pavement sections using the expected response framework. Compared with human-driven trucks, optimized lateral position could decrease pavement damage by 40%. Channelized traffic on the other hand could increase pavement damage by 60%. A simplified approach is introduced alongside a reliability analysis and fragility curves for various pavement structures. Distributed traffic was found to have the lowest probability of failure among all traffic scenarios.

Scheduling cross-docking operations under uncertainty: A stochastic genetic algorithm based on scenarios tree

A cross-docking terminal enables consolidating and sorting fast-moving products along supply chain networks and reduces warehousing costs and transportation efforts. The target efficiency of such logistic systems results from synchronizing the physical and information flows while scheduling receiving, shipping and handling operations. Within the tight time-windows imposed by fast-moving products (e.g., perishables), a deterministic schedule hardly adheres to real-world environments because of the uncertainty in trucks arrivals. In this paper, a stochastic MILP model formulates the minimization of penalty costs from exceeding the time-windows under uncertain truck arrivals. Penalty costs are affected by products' perishability or the expected customer’ service level. A validating numerical example shows how to solve (1) dock-assignment, (2) while prioritizing the unloading tasks, and (3) loaded trucks departures with a small instance. A tailored stochastic genetic algorithm able to explore the uncertain scenarios tree and optimize cross-docking operations is then introduced to solve scaled up instances. The proposed genetic algorithm is tested on a real-world problem provided by a national delivery service network managing the truck-to-door assignment, the loading, unloading, and door-to-door handling operations of a fleet of 271 trucks within two working shifts. The obtained solution improves the deterministic schedule reducing the penalty costs of 60%. Such results underline the impact of unpredicted trucks’ delay and enable assessing the savings from increasing the number of doors at the cross-dock. • This research proposes a two-stage stochastic model for cross-docking with uncertain trucks arrival times. • The model minimizes penalty costs due to deliveries violating the retailers time-windows. • A tailored Stochastic Genetic Algorithm based on Scenario Tree (SGA-ST) is proposed to solve real-world instance. • SGA-ST outperforms the two-stage stochastic MILP formulation solved with commercial solvers. • The SGA-ST is implemented into a user-friendly decision-support tool to aid practitioners in cross-docking operational decisions.

Vehicular impact resistance of highway bridge with seismically-designed UHPC pier

This study strives to numerically explore the performance of highway bridge supported by seismically-designed ultra-high performance concrete (UHPC) piers in resisting heavy truck impact. Firstly, six types of bridge piers are designed with considering two different concrete types (i.e., normal strength concrete (NSC) and UHPC) and three various seismic hazard levels (i.e., earthquake intensities (EI) of 7, 8, and 9) according to Chinese seismic design specifications, and the corresponding refined finite element (FE) models are established and validated by reproducing the tests of drop hammer impacting on reinforced NSC and UHPC members. Based on the well-verified FE models of simply-supported double-pier bent highway bridge and heavy truck, total 54 collision scenarios are carefully designed by referring to the actual accidents, and the vehicle-pier collision analyses are numerically performed by using the nonlinear FE analysis program LS-DYNA. Then, the effects of seismic fortification level and concrete type of impacted pier on the vehicular impact force and dynamic responses of entire bridge structure, as well as the damage and failure modes of both impacted pier and entire bridge are studied. It demonstrates the effectiveness of seismically-designed UHPC pier on improving the vehicle-impact resistance of bridge structure. Besides, more attentions should be paid to the safety of NSC-EI7 and UHPC-EI7 piers and the brittle shear failure in NSC-EI8 piers. Finally, aiming to quantitatively compare the anti-collision performances of entire bridge structure supported by NSC and UHPC piers under the identical seismic fortification intensity, a performance evaluation method of entire bridge structure is proposed based on the residual lateral displacement of the impacted pier. The present work can provide helpful references for the practical applications of UHPC in bridge piers and the on-site feasible evaluation of the residual performance of the post-collision bridge structure.