# Analyzing the Factors Influencing Time Delays in Korean Railroad Accidents
## 3 Data Descriptions  
### Overview of Railroad Accidents in Korea  
This section commences with a concise overview of railroad accident statistics. The investigation employed a dataset encompassing 22 years of railway accident data, culled from the Railroad Safety Information System (RSIS) spanning the timeframe of 2001 to 2022. The RSIS database features comprehensive historical records of accidents, including temporal specifics, causative factors, duration of train suspensions, fatalities, injuries, geographic coordinates, meteorological conditions, and other pertinent details. The dataset is classified into two distinct categories. The first category pertains to accidents primarily characterized by their detrimental impact on either human life or property and encompasses occurrences such as fatal train accidents (involving train-to-train collisions, derailments, or fires on trains), ground-level crossing accidents (involving train-to-human or train-to-vehicle collisions at ground-level crossings), and human-involved accidents (involving deaths or injuries resulting from train operations or other factors). The second category encompasses incidents that gave rise to perilous situations, exemplified by near misses, as well as events leading to time delays, such as those caused by train malfunctions or facility failures. Figure 1 presents the RSIS dataset, offering a comparative analysis of \"Incidents\" and \"Accidents\" during the years 2001 and 2022. Herein, \"Fatality\" encompasses the total number of deaths and/or injuries resulting from any railway accident. In 2001, the dataset records 498 \"Incidents\", a number that exhibited a noteworthy reduction to 227 in 2022. This reduction in \"Incidents\" is reflected in an annual growth rate (AGR) of \(-3.7\%\). Similarly, the data indicates a decline in \"Accidents\" from 710 instances in 2001 to a mere 80 occurrences in 2022. This remarkable decrease in \"Accidents\" corresponds to an AGR of approximately \(-9.9\%\). The negative AGR values underscore a substantial decline in both \"Incidents\" and \"Accidents\", with \"Accidents\" displaying a more pronounced reduction over the specified period. It is worth noting that, aside from an anomaly in the year 2014, where a train collision resulted in 477 injuries (based on the statement of accident overview in the data field of RSIS dataset, following a rear-end collision of a departing train from Sangwangsimni station with an incoming train on 2 May 2014), the number of fatalities per accident has remained relatively stable. The rationale for this development lies in the widespread adoption of state-of-the-art technological innovations, including advanced  
safety systems such as automatic train control, train radio communications, various grade level crossing solutions, and passenger safety doors. Notably, this period has witnessed the extensive implementation of these technologies by numerous railroad operators, coupled with the strategic repositioning of level-crossings to subterranean or elevated positions [8]. This study seeks to measure time delays caused by various accidents or incidents by analyzing the impact between time delays and factors such as season, size of train operators, type of railroad, accident cause, accident location, etc. Figure 2 represents the ratio of the number of accidents and incidents with time delay records. A total of 14,771 accidents and incidents occurred, and only 38.3% of them had a time delay record of 22 years on average. In detail, the proportion was only a small portion of 0.9% in 2001 and 2007, but increased noticeably to an average of 78.8% in the remaining years. In general, reporting of train accidents and incidents follows the guidelines on railway accident and investigation reporting. This guideline was established under the Railway Safety Act in November 2007, and serves to define the specific procedures and methods for reporting railway accidents. It aims to ensure the timely and accurate reporting of such incidents.