Congestion Evaluation of Pedestrians in Metro Stations Based on Normal-Cloud Theory
Round 1
Reviewer 1 Report
The study is interesting and in line with the journal topics. The paper proposes a methodology to evaluate the passenger crowd safety of the rail transit station and the possible solutions to increase the safety of the station in different conditions. Also, the methodology is applied to the metro transition station of Ningbo, China.
I would like to make some suggestions to improve the quality of paper:
For a better understanding of the case study, it is important to add some data on the transport characteristic of two metro lines (eg. number of trains per hour, number of total passengers, ...); Clarifying the number of weekdays of video recording that you consider (only 5 weekdays or all weekdays of April 2018?). Explaining whether the values of four metrics (P1-P4) are the average or the maximum values; In the Figure 3b, the graph is the same of Figure 3a; Improving the representation of input step in the conceptual model framework procedure (Figure 4). It is not clear that for the three felicities is not possible to calculate the whole indicators.
Author Response
Please refer to the attached
Author Response File: 
Author Response.doc
Reviewer 2 Report
Comments:
The results could be compared using another membership function, e.g. trapezoidal. You can also use a neural network to compare classification results.
Too short observation time (4 hours for each object, 17.00-19.00) does not allow to draw general conclusions.
Minor
1) There is an error in the summary, three levels of density are written, and then four are used.
2) Fig. 3
Figures a and b are the same. In b should be average walking speed (m/min). In addition, the values on the Y axis for P1 are not suitable. “when nobody exits at the facilities, the value of P1 is the facility area value”. Is the area value the same for pedestrians moving in both directions?
3) Units for P3 are different:
a) page 5, line 7 passenger flow in unit width [ped / (min * m)],
b) in the caption under the figure 3 c and on page 6, line 3 [ped / min * m]
c) page 6, Line 9, P3 = 25.63 ped / (m / min),
4) Fig. 4 suggests that all criteria (P1, P2, P3, P4) were taken into account for congestion level of pedestrians.
Author Response
Please refer to the attached
Author Response File: Author Response.doc
