Light Vehicles Research Articles

Improving Traffic Safety in Existing and New Road Tunnels with the Novel NDBA Concrete Safety Barrier

Abstract Two main elements are essential in terms of road traffic safety. The first element is accident prevention and the second is the minimization of accident severity once a crash has occurred. Concrete safety barriers have very good anti-collision performance against roadside obstacles, relatively modest construction and maintenance costs, and low dynamic deflection and therefore are widely used in tunnels. Thanks to their characteristic redirective profile these barriers can redirect errant vehicles into their original lane after collisions. However insufficient research has been done for increasing the performance of concrete barriers purposely designed for tunnel installations. This research presents the new “NDBA Tunnel” concrete safety barrier designed and constructed by the Italian Road Operator ANAS indicated to be installed in road tunnel sections for safety improvements. In Europe, road safety barriers must be designed in compliance with the European Standard EN 1317. Therefore, the barrier “NDBA Tunnel” was subject to the TB11 and TB81 full-scale crash tests according to the European EN 1317 regulation. The results prove the barrier's ability to absorb impact loads of light and heavy vehicles with a working width W2. Therefore, the NDBA concrete barrier can be installed on existing or new tunnels at a distance less than or equal to 70 cm from the facing of the tunnel wall.

Study on Discharge Characteristic Performance of New Energy Electric Vehicle Batteries in Teaching Experiments of Safety Simulation under Different Operating Conditions

High-voltage heat release from batteries can cause safety issues for electric vehicles. Relevant scientific research work is carried out in the laboratory. The battery safety of laboratory experiments should not be underestimated. In order to evaluate the safety performance of batteries in the laboratory testing of driving conditions of electric vehicles, this paper simulated and compared the discharge characteristics of two common batteries (lithium iron phosphate (LFP) battery and nickel–cobalt–manganese (NCM) ternary lithium battery) in three different operating conditions. The operating conditions are the NEDC (New European Driving Cycle), WLTP (World Light Vehicle Test Procedure) and CLTC-P (China light vehicle test cycle) for normal driving of electric vehicles. LFP batteries have a higher maximum voltage and lower minimum voltage under the same initial voltage conditions, with a maximum voltage difference variation of 11 V. The maximum current of WLTP is significantly higher than NEDC and CLTC-P operating conditions (>20 A). Low current discharge conditions should be emulated in teaching simulation and experiments for safety reasons. The simulation data showed that the LFP battery had good performance in maintaining the voltage plateau and discharge voltage stability, while the NCM battery had excellent energy density and long-term endurance.

APPLICATION OF PERMEABLE ASPHALT PAVEMENT CONSTRUCTION IN TRAFFIC AREAS

Lithuania’s total road network consists of more than 84000 km of roads, of which more than 21000 km are national roads. Roads of national importance are managed by the Lithuanian Road Administration. The remaining roads are classified as local roads managed by local governments. Road installation and maintenance often lead to the problem of surface water drainage and accumulation on the road surface. The aim of this study is to identify and propose the most appropriate permeable asphalt pavement construction to solve this problem, taking into account the purpose of the application and the class of pavement structure. The scope of the study identifies three recommended permeable asphalt pavement designs for the installation of DK 0.1-DK 1 pavement structures in ancillary streets, parking and recreation areas where light vehicle traffic with occasional heavy vehicle traffic. It has also been found that in areas of high traffic intensity, it is appropriate to use an alternative to permeable pavements – a permeable pavement design for the shoulder, where the roadway structure is impermeable to water and the shoulders are permeable to water (a permeable pavement structure is installed). The recommended permeable asphalt pavement structures, when properly selected, reduce the risk of flooding on the roadway.

Virtual Reality Sebagai Media Pembelajaran Teknik Kendaraan Ringan Otomotif Dalam Era Pendidikan Digital

During the aftermath of the Covid-19 pandemic, educational establishments encounter difficulties in providing comprehensive learning experiences due to the unpredictable circumstances caused by the pandemic. Hence, it becomes crucial for these institutions to prioritize the adoption of digitalized education that allows for accessibility at any time and from any location. However, the field of light vehicle engineering faces its own set of challenges when it comes to delivering intricate materials, primarily due to the size and intricacy of the learning resources. To tackle this issue, a novel approach has been introduced in the form of Virtual Reality (VR)-based learning methods, which prove to be invaluable tools in enhancing comprehension of the subject matter.

Faktor-Faktor Keterlaksanaan Merdeka Belajar Pada Program Studi TKR SMK N di Blitar

The implementation of Merdeka Belajar (MB) brings fundamental changes to Vocational High Schools (VHS). The MB curriculum that is implemented needs to be approached with a deep understanding of the concepts and processes. Thus, many factors influence its implementation. This research aims to analyze the factors in implementing independent learning in vocational schools. This research uses a qualitative approach with a multi-case study at two Public Vocational High Schools (PVHS) in Blitar through in-depth interviews supported by observation and documentation. The research results show that the independent curriculum implemented in PVHS has obstacles in the form of teacher misconceptions and difficulties in synchronizing the curriculum in Light Vehicle Engineering (LVE) with industry. The learning model used in LVE subjects to train students to work independently is PjBL. Meanwhile, guest teachers from industries are invited to provide training and insight to teachers and students. Furthermore, internships are carried out in LVE workshops and industry. Meanwhile, student competency tests are carried out involving the career center and school certification. LVE learning technology updates and graduate absorption also influence this. In conclusion, the implementation of the MB curriculum at VHS is determined by teacher awareness and leadership strategy choices.

Identifying interactions among factors related to death occurred at the scene of traffic accidents: Application of “logic regression” method

AimTraffic accidents are caused by several interacting risk factors. This study aimed to investigate the interactions among risk factors associated with death at the accident scene (DATAS) as an indicator of the crash severity, for pedestrians, passengers, and drivers by adopting “Logic Regression” as a novel approach in the traffic field. MethodA case-control study was designed based on the police data from the Road Traffic Injury Registry in northwest of Iran during 2014–2016. For each of the pedestrians, passengers, and drivers’ datasets, logic regression with “logit” link function was fitted and interactions were identified using Annealing algorithm. Model selection was performed using the cross-validation and the null model randomization procedure. Resultsregarding pedestrians, “The occurrence of the accident outside a city in a situation where there was insufficient light” (OR = 6.87, P-value<0.001) and “the age over 65 years” (OR = 2.97, P-value<0.001) increased the chance of DATAS. “Accidents happening in residential inner-city areas with a light vehicle, and presence of the pedestrians in the safe zone or on the non-separate two-way road” combination lowered the chance of DATAS (OR = 0.14, P-value<0.001). For passengers, “Accidents happening in outside the city or overturn of the vehicle” combination (OR = 8.55, P-value<0.001), and “accidents happening on defective roads” (OR = 2.18, P-value<0.001) increased the odds of DATAS; When “driver was not injured or the vehicle was two-wheeled”, chance of DATAS decreased for passengers (OR = 0.25, p-value<0.001). The odds of DATAS were higher for “drivers who had a head-on accident, or drove a two-wheeler vehicle, or overturned the vehicle” (OR = 4.03, P-value<0.001). “Accident on the roads other than runway or the absence of a multi-car accident or an accident in a non-residential area” (OR = 6.04, P-value<0.001), as well “the accident which occurred outside the city or on defective roads, and the drivers were male” had a higher risk of DATAS for drivers (OR = 5.40, P-value<0.001). ConclusionBy focusing on identifying interaction effects among risk factors associated with DATAS through logic regression, this study contributes to the understanding of the complex nature of traffic accidents and the potential for reducing their occurrence rate or severity. According to the results, the simultaneous presence of some risk factors such as the quality of roads, skill of drivers, physical ability of pedestrians, and compliance with traffic rules play an important role in the severity of the accident. The revealed interactions have practical significance and can play a significant role in the problem-solving process and facilitate breaking the chain of combinations among the risk factors. Therefore, practical suggestions of this study are to control at least one of the risk factors present in each of the identified combinations in order to break the combination to reduce the severity of accidents. This may have, in turn, help the policy-makers, road users, and healthcare professionals to promote road safety through prioritizing interventions focusing on effect size of simultaneous coexistence of crash severity determinants and not just the main effects of single risk factors or their simple two-way interactions.

Research on driving condition recognition in hybrid electric vehicle energy management strategy

Abstract The driving conditions encountered by vehicles during operation are complex and varied, and the ECMS (Equivalent fuel Consumption Minimization Strategy) based on minimum equivalent fuel consumption has poor adaptability to different driving conditions. To optimize the adaptability of the ECMS and improve the overall vehicle economy, this paper proposes an operating condition recognition model based on the Back Propagation neural network algorithm to optimize the ECMS energy management control strategy. Firstly, three types of driving conditions were identified: urban, suburban, and high-speed conditions. A complete vehicle model was constructed on the Matlab/Simulink platform. The efficacy of the strategy, before and after optimization, is verified under the WLTP (Worldwide Harmonized Light Vehicles Test Procedure) driving cycle. Simulation results show that the optimized ECMS can better adjust the power apportionment among the engine and motor, reducing the fuel consumption per hundred kilometers by 4.01% and thereby enhancing the overall vehicle economy.

Decelerating catalyst aging of natural gas engines using organic Rankine cycle under road conditions

High exhaust temperature is an intrinsic nature of natural gas engines which underlies power de-rating and thermal aging of after-treatment system; therefore, this study integrates an organic Rankine cycle (ORC) system between engine and it's three-way catalyst (TWC) to address these challenges. ORC facilitates power output enhancement through exhaust energy recovery and alleviates thermal aging by reducing exhaust temperature. To estimate the effectiveness of this hypothesized system, a simulation-based investigation is performed. First, simulation models, including engine, TWC, and vehicle dynamic models, are built and validated by experimental data. According to the temperature characteristics of different TWCs, three scenarios, representing old, current, and prospective TWC technology, are formulated to estimate the ORC performance under Worldwide Harmonized Light Vehicles Test Cycle. Results show that ORC system can substantially alleviate the thermal damage caused by high exhaust temperature and extend TWC lifespan. It is estimated that over 98.5 % of thermal damage can be decreased by proper ORC setting, and the average TWC lifespan extension can be at least 55.4, making a reduced noble metal usage and cost of TWC. Meanwhile, with the decrease of the working temperature of TWC, ORC can recover exhaust energy under more road conditions, further improving the net power and shortening the payback period of extra ORC hardware costs. A reduction in the working temperature of TWC from 770.5 K to 618 K yields a 109 % enhancement in maximum power, coupled with a 62.30 % reduction in the payback period. These findings fully reflect the advantage of ORC-TWC coupling and indicate that ORC is supposed to be used more for the TWC with a low working temperature to maximize economic effectiveness. This study provides a novel pathway for thermal aging alleviation of TWC and a valuable reference for prospective studies on matching ORC with TWC under road conditions.

Determination of stresses in dangerous cross-sections of frame spars of minitractor vehicles

Problem. On the basis of the method of initial parameters, it is necessary to determine the mass-dimensional parameters of the frame of the spar type, for the creation of a universal small-sized vehicle UMTZ-26 "Nadia", as well as for the development of a mini-truck of category N1, with a carrying capacity of up to 3.2 tons. Goal. To determine the value of the maximum forces (stresses) and moments acting in the structural elements of the spar frame during the arrangement of the engine with transmission, body, engine compartment and cabin of the UMTZ-26 "Nadia" light vehicle, as well as units and aggregates of the N1 category, which can be used for municipal city or farm purpose. Results. According to the given calculation using the method of initial parameters (for frame structures), the maximum load in the cross section of the selected channel is determined, which does not exceed 106.372 MPa, the latter is used as a spar in the welded frame of the vehicle. The maximum permissible load that this profile of the channel can withstand is 160 MPa. Originality. The drawing and design documentation of the spar type was developed, which was used for the development of new universal small-sized vehicles of the UMTZ-26 "Nadia" type, as well as for the creation of mini trucks of the N1 category. Practical value. The practical value lies in the fact that the values of the maximum forces and moments acting in the side members of the frame when the engine with transmission, the engine compartment and the cabin of the vehicle are arranged on it do not exceed the maximum permissible values and the latter can be used on mini motor vehicles of category N1.

Effects of fuel and driving conditions on particle number emissions of China-VI gasoline vehicles: based on corrections to test results.

The increasing number of vehicles are emitting a large amount of particles into the atmosphere, causing serious harm to the ecological environment and human health. This study conducted the Worldwide Harmonized Light Vehicles Test Cycle (WLTC) to investigate the emission characteristics of particle number (PN) of China-VI gasoline vehicles with different gasoline. The gasoline with lower aromatic hydrocarbons and olefins reduced particulate matter (PM) and PN emissions by 24% and 52% respectively. The average PN emission rate of the four vehicles during the first 300s (the cold start period) was 7.2 times that of the 300s-1800s. Additionally, because the particle transmission time and instrument response time, the test results of instantaneous emissions of PN were not synchronized with vehicle specific power (VSP). By calculating the Spearman correlation coefficient between pre-average vehicle specific power (PAVSP) and the test results of PN instantaneous emissions, the delay time was determined as 10s. After the PN emissions results were corrected, the PN emissions were found to be more related to VSP. By analyzing the influence of driving status on emission, this study found that vehicles in acceleration mode increased PN emissions by 76% compared to those in constant speed mode.

Experimental Research on Regulated and Unregulated Emissions from E20-Fuelled Vehicles and Hybrid Electric Vehicles

Ethanol as a renewable fuel has been applied in fuel vehicles (FVs), and it is promising in hybrid electric vehicles (HEVs). This work aims to investigate the emission characteristics of ethanol applied in both FVs and plug-in hybrid electric vehicles (PHEVs). The paper conducted a real-road test of an internal combustion FV and PHEV, respectively, based on the world light vehicle test cycle (WLTC) by using gasoline and regular gasoline under different temperature conditions. The use of E10 and E20 in FVs has been effective in reducing the conventional emissions of the vehicles. At 23 °C, E10 and E20 reduced the conventional emissions including carbon monoxide (CO), total hydrocarbon compound (THC), non-methane hydrocarbon compound (NMHC), particulate matter (PM), and particulate number (PN) by 15.40–31.11% and 11.00–44.13% respectively. At 6 °C, E10 and E20 reduced conventional emissions including THC, CO, and PM by 2.15–8.61% and 11.02–13.34%, respectively. However, nitrogen oxide (NOX) emissions increased to varying degrees. The reduction trend of non-conventional emissions including methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) from FVs fueled with E10 and E20 is not significant for vehicles. Overall, the emission reduction effect of E20 is better than that of E10, and the emission reduction effect of ethanol gasoline on vehicle emissions is reduced at low temperatures. Lower ambient temperatures increase vehicle emissions in the low-speed segment but decrease vehicle emissions in the ultra-high-speed segment. HEV emissions of THC, CO, PN, and PM are reduced by 25.28%, 12.72%, 77.34%, and 64.59%, respectively, for E20 compared to gasoline, and the use of E20 in HEVs contributes to the reduction of overall vehicle emissions.

Adaptive extended kalman filter for PEMFC membrane water content estimation

Proton Exchange Membrane Fuel Cells are a favorite technology for decarbonizing the transportation sector. However, their large-scale democratization is hampered by their high cost compounded by their unsatisfactory lifespan. To anticipate potential degradation while keeping improving performance, it is essential to maintain an acceptable humidity range inside the cells, especially at the membrane level. However, membrane humidity level is not directly measurable, alternative techniques must be considered to recover this key variable. Here, we develop a real-time software sensor of the membrane water content at the fuel cell’s heart. We build a model describing the membrane water balance, electrochemical behavior, and species mass balance. We then reduce the model and perform an Adaptive Extended Kalman Filter. We perform sensitivity analyses in both steady-state and transient conditions. We validate the filter on a “Worldwide Harmonized Light Vehicles Test Cycles” test procedure. Finally, we obtain a fast and accurate model-based software sensor.

Electric vehicles as an emission mitigation option: expectations and reality

AbstractGlobally, the reliance on thermal power, constituting 67% of electricity generation, prompts questions for many countries regarding the viability of electric vehicles (EVs) for emission reduction in the transportation sector. This study comprehensively analyzes CO2 emissions in the small family car segment, considering engines powered by different energy sources. The analysis is coupled with Worldwide Harmonized Light Vehicle Test Procedure driving profiles, accounting for specific ambient temperature structures representative of densely populated areas in Türkiye. The constructed model incorporates the hourly temperature of the relevant cities and the hourly electricity production mix by considering the indirect emissions and comparing the ICEVs (Internal Combustion Engine Vehicles) and EVs in different time frames from 2015 to 2020. The resulting emissions from each vehicle type in each city and driving profile, along with the ratio of instances in which EVs exhibit higher emissions than ICEVs, are presented.The findings reveal the intricate interplay between vehicle type, climate conditions, and driving profiles. While the urban driving profile emerges as superior for EVs regarding CO2 reduction, offering a comfortable driving experience without range anxiety and mitigating local pollutants, it exhibits less significant carbon emission reductions at lower and higher speed profiles, particularly in cold climate conditions. EVs are not a silver bullet but a valuable technology for emissions reduction under specific conditions. Policymakers are urged to consider factors favoring EVs over ICEVs regarding CO2 emissions, such as driving profiles, time and climatic conditions when formulating investment policies and subsidies. Graphical abstract

Integrating hybrid PV/wind-based electric vehicles charging stations with green hydrogen production in Kentucky through techno-economic assessment

The study presents a comprehensive analysis of the integration of Photovoltaic (PV)/wind systems with electric vehicle (EV) charging stations, enhanced by green hydrogen production based on existing EV load profiles across Kentucky. It explores the use of excess PV energy to charge Lithium-ion batteries, potentially supplemented by on-grid power during periods of lower electricity costs. The research includes the development of predictive models for hydrogen production and its subsequent use in hydrogen-powered vehicles. The techno-economic assessment reveals that such integration exhibits consistent economic viability, with minimal variations in key financial indicators like the levelized cost of electricity, payback period, and PV/wind energy fraction. The study also highlights green hydrogen production for on-grid PV/wind power charging the electrolyzer leads to the highest production cost (∼13 USD/Kg) compared to off-peak grid and a grid/PV/wind combination (∼6 USD/Kg). The projected hydrogen output is poised to support a significant number of light and heavy-duty vehicles by 2040, indicating promising potential for low-carbon transportation in Kentucky.

Islamic religious education learning innovations in strengthening character education in the Industrial Revolution Era 4.0

&lt;p&gt;This research is based on the role of Islamic Religious Education (PAI) subjects in strengthening student character in the era of Industrial Revolution 4.0 at SMK Muhammadiyah 1 Bantul. In connection with this, this research aims to determine Islamic religious education (PAI) learning innovations in strengthening the character of the Industrial Revolution 4.0 at SMK Muhammadiyah 1 Bantul. This research uses qualitative research methods, which are delivered descriptively. Sources of information in this research include school principals, teachers, education staff, and students who participate in learning activities in class XI of the Automotive Light Vehicle Engineering Skills Program (TKRO) at SMK Muhammadiyah 1 Bantul. The primary data source is in the form of the words and actions of the subject, which is the focus of the research; the rest is in the form of additional data such as documents, photos, and others. This research concluded that the "Kaizen" method, which originates from Japanese, the Japanese concept of Continuous Incremental Improvement, can strengthen character education and become a PAI learning innovation in the era of the Industrial Revolution 4.0. The "Kaizen" method includes five stages with the prefix "S": Seiri, Seiton, Seiso, Seiketsu, and Shitsuke.&lt;/p&gt;

Experiment investigation for interconnected effects of driving cycle and ambient temperature on bidirectional energy flows in an electric sport utility vehicle

The constrained driving range has emerged as a pivotal quandary impeding the advancement of electric sport utility vehicles (ESUVs). In this study, energy flow tests were executed on an ESUV to investigate interconnected effects of driving cycle and ambient temperature on bidirectional energy flows throughout the entire driving range. The results reveal that air conditioner singularly imposes a substantial surge in energy consumption at high-temperature settings. Notably, energy utilization efficiency (ηuti) reaches its zenith under Fixed speed cycle at room temperature (FSR_R) and energy recovery efficiency (ηrec) attains its peak under World Light Vehicle Test Cycle at room temperature (WLTC_R). Nevertheless, ηuti and ηrec attain their acme at room temperature and reach their nadir under low-temperature conditions, regardless of the specific driving cycle employed. Battery average temperature exhibits an ascending trajectory at room temperature and displays cyclic fluctuations at high temperature, while first increasing rapidly and then decreasing gradually in low-temperature ambient. Battery output energy per cycle initially decreases and eventually stabilizes with increasing the cycle count, and the battery recovery energy shows an initial upward trend followed by a stabilization phase. These findings provide empirical substantiation and prescriptive insights for mitigating energy consumption and enhancing driving range of ESUVs.

Mathematical model of a lightweight three-axle off-road vehicle construction for Arctic zone of Russia

Introduction. The model and results of calculating the smoothness of a light three-axle off-road vehicle for the Arctic zone of Russia are considered. The model on standard approaches and uses a system of assumptions that limits the number of degrees of freedom for the vehicle body to three, as well as one degree of freedom for the unsprung masses is based. The mathematical model is a system of ordinary differential equations and is supplemented with the necessary algebraic equations, as well as initial conditions. The system is integrated using the 4th order RungeKutta method, for which a program was written in C++. The calculations presented in the article demonstrate the possibility of conducting research on the smoothness of a vehicle under conditions of arbitrary terrain, typical for off-road conditions in the winter conditions of the Arctic zone. The dimensions and other parameters of the vehicle were taken from a full-scale model that was used in real expeditions in 2003-2019. Based on the model, suspension characteristics will be developed for a new all-terrain vehicle.Theory. When operating a wheeled vehicle in a wide range of conditions, even in northern regions, transverseangular vibrations are very often insignificant, so only vertical linear and longitudinal-angular vibrations of the frame can be considered. This problem enables to construct a system of equations of vehicle motion using selected degrees of freedom. From a mathematical point of view, these equations are classified as second-order ordinary differential equations with a variable structure of the right-hand sides, which reflects the non-linear nature of the behavior of the suspension in terms of its geometric constraints.Methods. The work uses numerical methods to solve the equations of the constructed model, which enables to gradually weaken the accepted assumptions and build more general calculation algorithms. The main integration method for ensuring the stability of solutions is the multi-step Adams method, which, with the correct choice of step, ensures the necessary stability of the solution over sufficiently long model times. However, in this work, the 4th order Runge-Kutta method was adopted, which turned out to be quite sufficient.Results and conclusions. The paper presents the results of a numerical study of the oscillatory processes of an off-road vehicle during uniform translational motion of the vehicle on a horizontal surface with a given profile of irregularities. The graphs show a transition process of oscillations, which ends with reaching a steady state. The shape of oscillations in a steady state can be irregular and significantly depends on the given speed of the all-terrain vehicle. Analysis of the dependencies presented in the figures shows that the shape of the oscillations of the allterrain vehicle’s frame, as well as the amplitude and frequency, significantly depend on the speed of the vehicle (at a constant road profile). Changing the road profile leads to corresponding changes in the forms and characteristics of forced vibrations of a vehicle on a suspension, which makes it possible to build the necessary amplitude-frequency characteristics, optimize the elastic and dissipative parameters of suspensions, optimize their number and location, and also monitor the movements of arbitrary points at which various units are located.

Suitable solutions and EU regulatory framework of electric light mobility vehicles for last-mile delivery: an overview

Due to current environmental European regulations in terms of pollutant emissions, electric cargo cycles are receiving growing interest compared to heavy-duty vehicles as a cheaper and healthier alternative for last-mile delivery of goods in urban and suburban areas. Within the PNRR Next Generation EU program, the Sustainable Mobility Center aims to design innovative e-cargo bikes considering technical features along with rider behaviour and infrastructure characteristics. The market offers plenty of solutions, which may differ in technical and design features. Nowadays a standardized terminology, widely shared among researchers for those light mobility vehicles does not exist. Several authors employ different terms or introduce classifications based upon the vehicle type of use or even on the vehicle layout (e.g., payload position or number of wheels). Concurrently, EU regulatory framework is undergoing rapid changes and appears unclear. Certain categories of light mobility vehicles might be ruled out from the type-approval system established by the regulation EU 168/2013. For those vehicles, harmonised standards are under drafting or approval. This situation requires a considerable effort among manufacturers in the identification of the proper product directives or regulations and the associated mandatory requirements and testing procedures for the introduction of a new vehicle model in the market. Within this context, an overview of the EU regulatory framework for these light mobility vehicles is presented. A literature evaluation with a structured and coded methodology of scientific databases, company websites and commercial reports is performed, evaluating commercial and prototype solutions of e-cargo bikes from a technical and legislative perspective. Furthermore, a case study is addressed, deepening the national legislation which rules the use of e-cargo bikes in Italy. The information provided in this work may be useful among manufacturers as a starting point for the design process of these types of vehicles. Moreover, this paper lays the foundations for a widely recognized taxonomy of e-cargo bikes based upon distinctive features.

Interaksi Faktor-Faktor Penyebab Kecelakaan di Jalan Tol dengan Kesenjangan Kecepatan sebagai Pemicu Kejadian Tabrak dari Belakang pada Malam Hari di Jalan Tol Cipali

Traffic accidents due to rear-end collisions are the highest contributor to the death rate in traffic accidents that occur on toll roads. It is suspected that vehicle, environmental, weather and driver factors as well as high speed gaps contribute to the occurrence of accidents. This study aims to determine the relationship between vehicle, environmental, weather and driver factors with the occurrence of speed gaps through observations of rear light brightness levels, vehicle visibility and speed. This study uses a descriptive observational method. The sample is a vehicle that passes through the Cipali Toll Road KM 188-108 towards Jakarta, on Sunday, January 29, 2024 at 19.30-21.00 WIB. The observer vehicle speed is 80-100 km/hour. The brightness level is measured using a luxmeter. The results of the study obtained dark weather, no rain, some toll roads did not have street lights, there were 316 minibus, bus and truck vehicles that passed or passed the researcher's route. A total of 240 vehicles (75%) of the minibus type had appropriate rear light brightness, visibility and speed. As many as 56 vehicles (23%) of the truck type had low rear light brightness, poor visibility, and speeds below regulations, resulting in a high speed gap which has a high potential to cause rear-end collisions.

Finite element analysis of a FeC, Cr-V and Al 7075-T6 leaf springs for light vehicle suspension system

This study has become very necessary because of the current condition of the roads in our country. The study is conducted to come out with an alternative best, cheapest, and available material for the design of leaf springs to prevent or reduce vehicle breakdown due to the breaking of the leaf spring on roads. Weight reduction is one of the main focuses of automobile manufacturers in this modern era. The objective of this study is to model and analyze a leaf spring for a light vehicle suspension system with Plain Carbon Steel (FeC), Chromium Vanadium steel (Cr-V), and Aluminum 7075-T6 as the implementing material using Finite Element Method (FEM). Aluminum 7075-T6 is very strong, and durable and will help in weight reduction since the axle leaf spring arrangement also adds weight to the vehicle. The study showed that, when the applied load of 3359.94 N was induced on the aluminum 7075-T6 leaf spring, the result was superior compared to the other materials with the same loading condition. The aluminum 7075-T6 leaf spring was observed to withstand deformation, strain, and stress better due to its superior properties. The study concluded that Aluminum 7075-T6 material should be adopted for manufacturing leaf springs and similar automobile components since it is light, strong, and can withstand greater forces.