Homothetic Behavior of Betweenness Centralities: A Multiscale Alternative Approach to Relate Cities and Large Regional Structures

Round 1

Reviewer 1 Report

The authors use the Normalized Angular Choice (NACH), derived form betweenness centrality to test the homothetic behaviour of road circulation networks across scales. The algorithms are properly used and the results are consistent with the purpose of the paper.

Still, there are some issues concerning the realistic use of the road networks at provinces and municipalities scale. The shortest paths towards all potential OD destination are appropriate for computing betweenness centralities for provinces model. But considering the real allocation of traffic flows in urban networks, the users travel between OD pairs through different routes, taking into consideration other measures of performance (travel time, number of stops, infrastructure characteristics, congestion etc.). Thus there is no single connection among the OD pairs to be used. Thus, in real terms, could be differences between the two models, that are not taken into consideration. Please add considerations about the realistic use of road networks at municipalities level and how could the algorithms be further adapted.

Author Response

We kindly thank the reviewer for the suggestions, which were appreciated and taken into consideration during the paper revision. We addressed bellow, point-by-point, the changes made. 

1. Added a footnote (footnote 8 - p.4) that briefly addresses the "preferential routes" terminology and highlight the characteristics of NACH. Being a measure that considers only the road-circulation network configuration to determine the shortest paths in OD pairs, the measure only assesses the probabilistic "movement demand" of a particular road section. While these probabilities have a significant correspondence with real-time movement, accurately predicting it in normal conditions (as measured by other authors referenced in the paper), NACH does not intrinsically take into account the real-time conditions pointed out by the reviewer (i.e. congestion, travel time) or more "movement supply" oriented features (i.e. infrastructure characteristics).  
2. Added a paragraph in the discussion (lines 247-253) addressing the issue of real allocation of traffic flows. It is correct - and was sharply pointed out - that the conditions exposed by the reviewer (i.e. congestion, temporary road obstructions, increases in travel time due traffic) could sure change the overall real-time flow allocation in each road-element; nevertheless such point does not seem to invalidate the model, nor the found homothetic behaviour usefulness. The model proposition is not intended to be a an exact representation of real-time movement conditions, but instead, is tailored to provide a predictive instrument, able to represent the overall movement demands, or the expected  through-movement,  in each road-element. The recursive homothetic behaviour indicates that these general movement demands (in normal conditions) do not change significantly when scales are increased. In this sense homotheties can help to construct regional analyses for movement logics with accurate predictions in shorter time-lapses. 
3. Added a paragraph in the conclusion (Lines 452-458) remarking that movement demand-oriented models, such as that presented in the paper, could be associated to other models that consider different measures of performance, taking into account the points made by the reviewer. 

In hope that you find the revisions satisfactory, 
 
Diego Altafini 
 
Valerio Cutini, 

Reviewer 2 Report

The paper is well written, and it presents a good example of the regional configuration for cities' sustainability. The methodology and the case-study description are well presented. In my opinion, conclusions are the weakest part of the paper. I would like to have a more explicit reference to policy recommendations (or policy implications). In my opinion, this paper could be more appealing to scholars in the field of spatial planning if the conclusions will underline not only technical issues but also territorial considerations. In other words, the results of the cartographic representation of configurational properties can be an influential lever for changing the current policies of the Tuscany Region?

Author Response

We kindly thank the reviewer for the suggestions, which were appreciated and taken into consideration during the paper revision. We addressed below, point-by-point, the changes made:

1. Added a paragraph (Lines 452-459) in conclusion pointing about possible territorial policies regarding Tuscany, mentioning that improvements in the map construction methodology can be useful to the evaluation of economic activities displacement and resilience. More importantly, we point out how considering the movement demands - alongside other methods that verse about the movement supply, can aid into identifying areas that are more territorially exposed in Tuscany, an relevant aspect when considering the divestment of regions.

While highly appreciating the suggestion, we cannot but remark, however, that the paper objective was not to present an in-depth reflection about possible territorial policies and recommendations, but to address a theoretical problem in the construction of large scale road-circulation network representations. Hence, further discussions about these aspects would surpass the scope of the paper and therefore are pointed out as possible - and crucial – issues in the future developments of the research (as posted in lines 492-494).

2. Addressed English issues in the text, all alterations in the original text are marked in red and may be tracked using the word "Track Changes" feature.

In hope that you find the revisions satisfactory,

Diego Altafini

Valerio Cutini,

Reviewer 3 Report

-

Author Response

We kindly thank you for the revisions.

Since there are no specific comments, we hope that this new revision also continue to stand up to your standards.

Best Regards,

Diego Altafini

Valerio Cutini