## 2 Matching the Automatic Fare Collection Data with the Real-Time Train Operation Data
Circles, triangles, and plus signs represent groups of individual passenger's smart card data who have completed their trips from S07 to S11 with associated boarding and alighting times at those stations. Train number 477 arrives at the S07 at 7:25:56 and S11 at 7:38:02. Any potential passengers who were on train 477 during the  
Figure 1: Route map and the station ID of Shinbundang S line. trip must be on the 2 nd quadrant of the horizontal and vertical lines intersecting at train 477. If the passengers used train 477, they must pass the boarding gate at S07 station before train 477 arrives at S07 station, and must also align after the train arrives at S11 station. Therefore, the group of passengers surrounded by the dotted lines roughly represents all of the potential users of train 477 from S07 to S11 station. It is noted that there were some passengers who boarded and alighted at the same stations, and these were excluded from the analysis. Figure 3: Entry-exit map of the trip from Jeongja (S07) station to Yangjae (S11) station. Figure 2: Smart card-based passenger information matching process against the real-time train operation data. Figure 4 shows the number of passengers boarding, alighting, and arriving onboard at each station on the S line. Trains depart from the right towards the left, and each line in each graph represents a train. Red lines represent trains operated during the morning peak-hours from 6:30 a.m. to 10:30 a.m., and blue lines represent trains run during the afternoon-peak hours from 6:00 p.m. to 9:00 p.m. Trains run outside of peak-hours are represented by gray lines. Figure 4 shows passenger boarding, alighting and onboard counts. When observed from the right, starting with the first station S01, in the morning peak, the boarding counts from S01 to S08 stations, inclusive, are significantly higher than the rest of stations combined. This is due to the fact that the regions covered by stations from S01 to S08 are dedicated residential areas (bed towns) of the Greater Seoul Area (GSA), S09 and S10 are located in an outskirts of Seoul, and S11 and S12 are located in the CBD of Gangnam area of Seoul. During the evening peak period, boarding counts at the S08  
Figure 4: **(a)** The number of boarding passengers at each station. (**b**) The number of alighting passengers at each station. (**c**) The number of onboard passengers when the train had been arrived at each station. station stands out as there is also a large concentrated commercial area called \"Pangyo Techno Valley\". This area is also related to the high number of alighting at S08 in the morning. During the morning peak-hour period, at stations from S01 to S06, inclusive, and S09, there are nearly zero alighting passengers. At S07 and S08 stations, some passengers alight, while most of the passengers alight at S11 and S12 stations in the CBD. There are relatively high numbers of alighting passengers at S07 and S08 compared to other residential areas because there are concentrations of office buildings near those stations. Note that S07 and S08 also serve as transfer stations connected with other metro lines. In the case of station S09, there are only residential facilities near the station, hence resulting in very low alighting counts. In the afternoon-peak and non-peak periods, most alighting counts occur at S11 and S12 stations. Due to the various characteristics mentioned earlier, the onboard passenger counts, as shown in Figure 4c, continue to increase as trains approach the final station S12 in the CBD. It is also noted that most trains in the morning-peak period experience passengers occupying at the full capacity of the trains and even exceeding the capacity with a factor of 2 between the S07 and S11 stations.