# System Proposal for Mass Transit Service Quality Control Based on GPS Data
## 5 System Overview
### The SQCM
#### 5.2.1 The Improved Transport Network Model
Figure 7: (**a**): aerial photo showing the location of the 7 unique points on the route. (**b**): photograph of point 5. (**c**): photograph of point 7. The tracking phase was applied to this data set, and 617,195 position records were selected for 9675 line services on route 210 in 2015; these data form the set \(AVL_{210,2015}\). The filtering phase was applied to this set of GPS data, and verified 8572 line services for which the recorded data sequences represented complete and consistent routes; hence the set \(QAVL_{210,2015}\) contained 222,382 position records. Once the GPS data had been filtered, we obtained the arrival times at each stop on each line service. The timetables of the line services on this route are scheduled by passing time, with two day types: one the one hand, weekdays (Monday to Friday), and on the other hand, weekends and public holidays. The results correspond to the two types: first, the results for weekday line services starting at 07:40 a.m., and then the earliest Sunday service, which starts at 8:40 a.m. Figure 8 shows the arrival times at each stop for the first set of line services, those that run from Monday to Friday. The horizontal axis represents the stops in order, i.e., the value 1 is associated with the first stop on the route, 2 with the second and so on until the last stop of the route, which has the value 30. The blue line represents the scheduled passing time, the average passing time is represented by the orange line, the earliest passing time by the yellow line, and the latest passing time by the grey line. Figure 9 shows two box-and-whisker plots displaying the percentile distribution of the AD metric at each stop on the route for line services that start at 07:40 from Monday to Friday (plot (a)) and for each stop on all line services that start at 08:40 on Sunday (plot (b)). In the plots, the value 0 on the vertical axis represents perfect timetable adherence, each band inside the boxes represents the median value, i.e., the delay value below which 50% of the AD values are located. The circles represent outliers: very small, very large or very rare values. As can be seen, the line services on Sundays are much more punctual than those that run on weekdays, possibly due to the difference in traffic congestion between weekdays and Sundays. We may also note that, for weekday line services and for most of the stops, delays continue or increase the further along the route the bus is, ranging from 2 to 8 min. By contrast, on Sunday line services, the increase and decrease in delays at stops does not follow a fixed pattern, and the median value is maintained between 0 and 5 min.The AD parameter values for each stop of the line service on the route are displayed in Figure 10, irrespective of day type and time. The median values for delay times are represented by colours: the green stops indicate a median value of less than 1 min, blue stops a median

Figure 8: Passing times of line services starting at 07:40 Monday to Friday, excluding public holidays. value between 2 and 3 min, light orange stops between 4 and 5 min, dark orange stops between 6 and 7 min and, finally, the red stops represent a median delay value of more than seven minutes. Figure 9: Box-and-whisker plots showing median values for the AD metric at each of the stops on the route for line services that run from 07:40 from Monday to Friday (plot **(a)**) and from 08:40 on Sunday (plot **(b)**). Figure 11 shows the RTV value for each type of line service. Graph (a) shows the values for weekday services (Monday to Friday). Graph (b) shows the values obtained for Sundays. Comparing the figures, it may be seen that punctuality varies according to the day type: the line service is less punctual on weekdays than it is on Sundays. The explanation for this is that there is less traffic on Sunday and there is lower demand at that time, so the buses run more smoothly and quickly, and are thus more punctual.