# Estimation of Driving Direction of Traffic Accident Vehicles for Improving Traffic Safety
## 5 Discussion and Conclusions
The proposed method can also be used to generate collision diagrams for traffic accident analysis. The crash diagram is an essential aspect of the crash report as the investigator can show the relationship that existed during the crash between the vehicle and the surrounding environment. According to DMV-349, written by the North Carolina Department of Transportation's Department of Motor Vehicles, it is recommended to include the \"direction of travel for each traffic lane\" when drawing crash scene diagrams. Therefore, the proposed method can help create a collision diagram by effectively estimating directions by referring to accident points and destination points, even in scenarios where direction information is not documented. On the other hand, the proposed method has some limitations. First, the utilization of estimated directional information raises concerns about reliability in terms of accuracy. Specifically, the proposed method estimates the destination information from the Report field. It selects the final destination as the closest location to the accident site in cases where a precise location is not found. As a result, the propagation of errors in multiple estimation stages compromises the overall reliability. Additionally, unlike the recording method used by the North Carolina Department of Transportation Division of Motor Vehicles, which includes four directions encompassing north, south, east, and west, the proposed method only considers the Northbound and Southbound directions, resulting in a limitation of limited directional information for traffic accidents. In addition, the proposed method generally overlooked various parameters related to traffic accident risk because it is intended only to estimate the direction. From this perspective, future work will involve researching estimating directionalities in terms of angle units in addition to the compass directions. To accomplish this, a road navigation API can be utilized to generate a repository of road journeys, enabling the determination of the precise direction of movement from the accident site. Furthermore, there is a need for research on traffic safety from various perspectives, exploring risk levels based on multiple factors by integrating various parameters associated with traffic accidents. For instance, factors such as the speed of the vehicles and time of the day (off-peak and on-peak), and also traffic volumes during peak periods, can be incorporated in this regard. In addition, recent developments in \"autonomous driving scenarios\" are being researched based on existing traffic accident overview data [31]. Therefore, the method defined in this paper, which uses rule-based NER, is expected to help develop new autonomous driving scenarios. Conceptualization, M.C. and Y.L. ; methodology, M.C. and Y.L. ; software, J.P. and S.K. ; formal analysis, J.P.; investigation, S.K. ; resources, M.C. ; writing--original draft preparation, J.P. and S.K. ; writing--review and editing, M.C. and Y.L. ; visualization, S.K. ; supervision, Y.L. ; funding acquisition, M.C. All authors have read and agreed to the published version of the manuscript. **Funding:** This work was supported by Institute for Information & communications Technology Planning & Evaluation(IITP) grant funded by the Korea government(MSIT) (No.2021-0-01352, Development of technology for validating the autonomous driving services in perspective of laws and regulations). **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable. **Data Availability Statement:** Not available. **Conflicts of Interest:** The authors declare no conflict of interest.