Automobile Crash Investigation Based on Vehicle System Related Causes: Systematic Literature Review

Automobile accidents are one of the leading causes of death worldwide. Every year, over 1.24 million people are killed in traffic accidents. Even though automobiles are designed to help people, they have been used to kill them in large numbers. Automobile accident research has primarily focused on past tragedies to develop and implement policies to combat this pandemic. The aim of this systematic review is to assess the different methods used to investigate the vehicle system-related cause factors of road traffic accidents. Police report reports have served as a foundation for providing historical facts about the causes of automobile accidents. It has been observed that police reports have limitations when it comes to reporting the involvement of vehicle systems in causing a traffic accident. The majority of the research was conducted on articles that investigated vehicle system risk factors using statistical data. Following articles that used statistical data to investigate vehicle system risk factors, the inclusion criteria were chosen. Articles on traffic accidents published in Cameroon were included on the condition that they studied at least one traffic accident risk factor. Two hundred twenty-five distinct records were identified, and 155 full texts were screened for inclusion, resulting in the inclusion of 25 studies in the review. According to the findings, failure to break the braking system, tyre puncture, poor driving, speeding, and overtaking are the leading causes of automobile crash reports reported by police. The majority of the


Introduction
An automobile calamity is one of the key causes of death all over the world. According to [1], automobile accidents are the 3 rd cause of death in the world. Studies reveal that about 1.24 million individuals die each year as a result of traffic accidents. Majority of these deaths (85%) occur in poor countries. [2] predicted the high rate of Traffic injuries in the world, their report classified road accidents as the 3 rd cause of death in the world. The Global status report on road safety launched by WHO in December 2018, highlighted the number of annual road traffic deaths that reached 1.35 million. According to [3], road traffic accidents were the leading killer of persons in 2018. At the moment with the present pandemic (coronavirus), the position of road accidents as one of the major causes of death may witness a little change. Though this might not prove that the rate of accidents will reduce in the following years, the pandemic has reduced the number of people traveling, caused by the barrier measures during the pandemic. Every day, about 3700 people are killed in automobile vehicles, bus, motorcycle, bicycle, truck, or pedestrian accidents around the world. WHO had predicted the position of traffic accidents between 1998 and 2020 (Table 1).  [7] proposed the need to develop a protocol to avoid or prevent traffic accidents at the extreme level in order to reduce human loss. Minimizing the number of road accidents, will decrease the death rate caused by road accidents. Among the causes of accidents, driver's behaviourial mistakes are the highest causinmg factors. Accidents caused by faulty vehicles system are ranked the last category of accident cause factors. The number of road accidents caused by vehicle systems is far from being negligible [17]. Existing studies of automobile accidents had focused primarily on injuries caused by driver's error and road-related factors.
Surprisingly, limited effort has been devoted to identifying factors that increase the rate of accidents caused by vehicle systems. These systems may not directly be the cause of the accident but, can indirectly influence the causation of an accident.
Most accident researchers are based on post-data to analyse the situations of traffic accidents. The fact that most researchers or reporters don't say much about their contribution may stem from the fact that, they lack adequate information on how they might have caused or influence the accident. Panagiota et al. [18] evaluated accident causation models overtime which showed that there has been a shift from the sequence of events to the representation of the whole system. In terms of accident investigation procedures, there has been a steady shift from hunting for a single immediate cause to recognizing numerous causes overtime.
Since different models approach accident causation in different ways, methods linked to accident investigation models provide fragmented information regarding the cause of accidents. It is suggested that using a combination of model-method pairs could provide a more reliable Platform for accident analyses.

Research Design
A systematic approach to literature review was adopted to identify the different methods used to investigate the vehicle system-related cause factors. Scientific

Data Collection
Given the frequency of automobile accidents, the selection criteria sought to locate research that included cross-examination of the reasons for an accident including vehicle systems. The following publications were being chosen based on their use of statistical data to analyse vehicle system risk factors. Articles about traffic accidents in Cameroon were accepted on the condition that they study at least one traffic accident risk factor. Non-systematic reviews and clinical practice guidelines were excluded, as well as articles that reported changes in knowledge, attitudes, or other surrogate variables. Market studies, polls, survey data, and research papers with poor methodological rigor according to the critical analysis criteria of this study were rejected ( Figure 1).  had something to say the concern the participation of vehicle system (tyres, braking system, suspension, steering system seatbelt, etc.) in the causation of an accident. Each article adopted a particular methodology to analyse the situation of automobile accidents. The publications chosen ranged between 2000 and 2021.

Data Extraction and Analysis
This range was used to cross-examine publications that had assessed and reported on the participation of vehicle systems in accident causation.   Articles that deliberated on any vehicle system factor were adopted for studies.

Results and Discussions
More to that, the selected articles must be published from 2000 to 2021. Any article out of this range was excluded. All reviewed articles were equally excluded.
The year of publication of every studied material was stated ranging between A. T. Achiri et al.

Analysis
There is evidence that the occurrence of a traffic crash is the result of multiple contributory factors [41]. As addressed in this literature review, driver's behaviour, geometrical and environmental conditions all contribute to traffic crashes and collisions. Statistically significant differences between the distribution of causes or factors contributing to the accident occurrence have been proven depending on the driver's behaviour, environmental factors, and vehicle system [32] [42]. Hendricks et al. [33] classified the following contributing factors as follows: driver inattention 22.7%, vehicle speed 18.7%, alcohol impairment 18.2%, perceptual errors 15.1%, decision errors 10.1%, and incapacitation 6.4% [43]. Traffic accident statistics suggest that human errors contribute to major crash types. Long duration of driving is a substantial cause of fatigue-related accidents on motorways or major roadways [44]. Fatigue caused by driving for extended periods acutely impairs driver alertness and performance and can compromise trans-World Journal of Engineering and Technology portation safety [45]. Limiting to one factor of accident causation sounds vague as improper overtaking, improper cutting in, improper turning right or left, improper parking or stopping, following too close, drunk driving, careless driving, passing prohibited roads, failure to stop at the crossing, failure to use a seatbelt, aiding and abetting of violation, etc., always accompany over-speeding in crash occurrence and injuries. This information is essential to the understanding of the causes and the ultimate means of preventing automobile crashes. Crash data in most cases have been used just for mitigation of traffic accidents, but can be used as a basis to set insurance premiums laws and to formulate licensing policies. The initial evidence to collect or visualize an automobile crash at the incident is to monitor the nature of the crash. The nature of the crash results in the gravity of injury sustained. Road construction and traffic policy-making depend on the types of accidents recorded overtime, to propose solutions that will prevent the future occurrence of a crash.

Frequency of Methods Used to Study the Related Variables
A common factor of central importance in road safety management is the collection and use of accurate and comprehensive data related to road accidents. The interpretation of these data can lead to a better understanding of operational problems. it is a prerequisite for an accurate diagnosis of accident problems, assists in the development of remedial measures, and permit the evaluation of the effectiveness of road safety programs [46]. A comprehensive database is a basic prerequisite for any effective road safety initiative to be undertaken. Each agency, whether it is government or non-government, involved in road safety activity, should have a clear understanding of the nature, scale, and distribution pattern of the road accident difficulties they want to address. Figure 3 shows the investigating methods that were used to study the variables sorted from the selected articles.
These methods include statistical analysis, interview/questionnaires, and EVD (event vehicle data) and DBEDR (driver behaviour event data recorder).
Most articles used statistical data analysis (Table 2) to investigate the various automobile crash parameters. The data analysed were secondary data collected of an automobile crash overtime. Upon reporting an accident, the reporter is exposed to multiple factors, but it is left for him to judge and report what information is at his disposal. The data reported is kept for further exploitation by the concerned authorities, researchers, associations, or organizations.
Many methodologies and strategies have been exploited by reports to assess a crash incident. Among these tools are questionnaires. These tools are greatly used in data acquisition in the psychometric domain. With this method, a respondent is given an opportunity to report his own side of the story. Self-report can't guarantee an absolute truth of the evidence. The respondent cannot give an answer that will go against his favour. In another case, the respondent may not want to expose certain information concerning him/herself. They may consider that reporting the truth will inquire heavy fines on them. Nangana

Accident-Related Factor Based on Studied Article Sample
To predict, suggest, analyse, or solve a problem, a clear and defined methodology for gathering information, processing it, and presenting the results is necessary. Organizing and categorizing the diverse data and methods of analysis are very important. There are numerous aspects that contribute to the cause of an accident, and it would be impossible to list them all. The focus of the sample articles examined was on vehicle-related system factors. The majority of the variables are interdependent or linked to a number of factors (Figure 4). The system of human, vehicle, road components and road traffic are inextricably linked. When these relationships meet certain natural regulated boundaries, road safety is actually maintained. Despite the fact that a specific job for guaranteeing safe traffic is assigned to a person, a system for objectively evaluating other types of elements should be established [20]. Many accidents have occurred as a result of drivers' or vehicle owners' failure to perform preventive maintenance.
A large percentage of accidents occur as a result of poor maintenance, which includes failed brake systems, faulty wheel alignment, mechanical difficulties with wheels, and headlamp failure.
The vehicle comes with an active and passive security system that ensures the vehicle's safety. While the car is in motion, active safety systems are always on.
The main indicated vehicle risk factor in the study sample is brake failure ( safety system failed while the vehicle is in motion. It will be evident that the car will be involved in a collision. These questions must be asked before or after any investigations: Did any failure in the vehicle system cause the driver to lose control and/or contribute to a fatal road accident? If that's the case, what precise mechanism went wrong and why? Was this system badly designed, was there a manufacturing issue, was there inadequate maintenance, or was it something else entirely? Before putting a vehicle on the road, it should be thoroughly checked or inspected for road safety.
With a few notable exceptions, automobile accidents are usually examined to a greater or lesser extent to assign blame to defaulters. Only a few investigations have been conducted with the purpose of increasing road traffic safety. Many have been investigated in order to assign blame or accountability [47]. While safety suggestions are frequently given, they regularly fail to address the root cause of whatever went wrong [48]. An accident is not produced by a single element; rather, it is created by a series of events that can be linked together or considered separately. Even while human error causes the majority of accidents, when one occurs, it is almost always the result of one or more flaws in the automobile safety system.
It has been established that a greater understanding of real-world crashes is required in order to offer the automotive industry more reliable statistical data for various crash types. It's worth noting that accurate statistical data is essential to guide future improvements aimed at lowering the causes of car accidents. The evidence gathered at a car accident site is transient and time-sensitive. Some of this temporary evidence, such as tire traces, gouge marks, debris, paint or other materials, will fade or vanish altogether overtime. As a result, it's critical that a qualified forensic specialist inspects the scene as quickly as possible following the accident.
This will reduce reliance on police reporting for data collection and inquiry.

A. T. Achiri et al. World Journal of Engineering and Technology
When a police officer does not belong to the same class as the RTA victim, his or her reporting may be skewed. According to Lindquist et al. [49], police officers in the United States of America issued much more traffic penalties to drivers of different races than themselves. When it comes to tribal matters, this becomes even worse. To draw cuttings, bring in appropriate defaulters, and charge the proper sanctions, adequate reporting is essential. Assuming that the information entered in RTR (road traffic record) forms is a thorough inquiry that may be used in accident reconstruction is mistaken [48]. The road traffic officers at the site do not conduct an investigation into the collision; instead, they just record the information on the RTR. In order to learn from previous disasters and prevent future ones, a thorough accident investigation is essential [50]. The contribution of vehicle flaws to road accidents would remain unknown unless a thorough accident investigation is done.

Discussion
Eyong [51] conducted research to find out the influence of road safety and accident prevention in Cameroon. Traffic safety and accident prevention play a crit- Tsala [29] carried out research to better understand accident-related approaches on Cameroonian highways. Their findings showed a correlation between traffic accidents and signalling. Their case study focused on the Yaoundé-Douala roadway, which runs for around 242 kilometres. They created accident scenarios based on crashes on one hand, and road signalling on the other, using the qualitative method. There were eight scenarios identified for collision-related accidents. These include violations of the highway law, failure to signal a construction zone, driver indifference, poor parking, improper overtaking, the lack of a slightly higher bump, failure to signal damaged work, and no crossroads sign- Tsala et al. [30] studied the Douala-Dschang roadway. The purpose of their study was to look into the risk factors that lead to reckless driving and other related causes of road accidents on the Douala-Dschang highway in Cameroon.
They uncovered six factors that influenced an accident's causes. Accidents were caused by speed and negligence, as well as the accident's location, the type of vehicle to blame, the day of the accident, the hour of the accident, and the drivers' ages. All previous study was based on secondary data obtained overtime from police records. In

Conclusion
The last group, as a cause of automobile accidents, is the vehicle system, which accounts for 1% -15% of all accidents in most nations. The aim of this systematic review was to assess the different methods used to investigate the vehicle system cause-related factors of road traffic accidents. There is evidence that the occurrence of a traffic crash is the result of multiple contributing factors. Driver's behaviour, road geometries, and environmental conditions all contribute to traffic crashes and collisions. Statistically significant differences between the distribution of causes or factors contributing to the accident occurrence have been proven depending on the driver's behaviour, environmental factors, and vehicle system. Furthermore, the cross-examination of studied samples evaluated the cause factor investigated and the method used to scrutinize these factors. The research work was largely restricted to studies that looked into the role of vehicle systems as a causal factor of an accident. The other risk variables were not taken into account. Despite the fact that several samples looked into certain parts of driver tation. There are virtual, limited policies on how to execute transportation policies targeted at reducing the high accident rate. Vehicle systems and road infrastructures are rarely included in reviews from developed countries. This is because they may be in charge of creating and enforcing transportation legislation that governs the industry. The inspection of a vehicle is not something to be taken lightly. If found to be faulty, the concern pays a hefty fine. High-Income Countries (HIC) are currently concentrating their efforts on examining driver behaviour and driving altitude. Owners and drivers of automobiles are required to respect road traffic regulation. To preclude the shortcomings of the existing reviews, we are proposing included reporting samples and technological solutions that will monitor and better report the participation of vehicle system in the causation of an accident. This will enhance the investigation and reporting of the causes of automobile crash causes including all the risk factors.