Sustainable City Evaluation Using the Database for Estimation of Road Network Performance

Round 1

Reviewer 1 Report

This paper presents a methodology to generate a large set of representative individual driving cycles through OSM road networks by referencing the Worldwide Harmonized Light Vehicles Test Procedure. The proposed DERNP was implemented using the PHEMLight5 emission framework and allowed for efficient estimation of relevant RNP parameters based on simple air distance calculations.

Overall, the manuscript is well-written and supported by fruitful literature. One minor suggestion is that the paper is too lengthy. However, it's not required to change since MDPI journals do not have page limit.  So, congratulations on this high quality manuscript for your own special issue.

Author Response

Dear reviewer,

Thank you very much for your kind words and the time you spent on reviewing our article.

We agree that the paper is rather lengthy and did another pass to cut down on less relevant paragraphs as well as tables. This brought the page count down to 25 pages (from 28). When accounting for text only, our article is 14 pages long (in the MDPI/Sustainability layout).

We would like to thank you once again for your feedback and the time you spent reading our work!

Reviewer 2 Report

Dear authors, please find the comments given below:

-Can you please reorganise the numbers in Table 3?

-Line 255: Please specify why did you choose these dates and hours for this research.

-The manuscript is very long. Can you please reduce the number of pages?

Author Response

Dear reviewer,

Thank you very much for the time you spent on reviewing our article and the valuable feedback you provided.

We reorganized Table 3 (now Table 2 due to the exclusion of a previous table) by rounding all numerical numbers to a maximum of 3 digits as well as better formatting and aligning those numbers at the decimal points. We feel that this greatly improved the visual clarity of the table and additionally allowed us to increase the font size for better readability.

We also specified and explained the limited time frame from July to September directly within the article as follows:

“All tile references in this article rely on a set of HERE traffic data retrieved in between July 25, 2022 and September 10, 2022 at five different timestamps (08:00 a.m., 09:00 a.m., 12:00 p.m., 02:00 p.m., and 04:00 p.m.). Traffic data is held constant for purposes of reproducibility within this article but should be updated in regular intervals. The selected time frames are related to main working hours of German transportation service providers. Additional time frames can be considered if relevant to the underlying business case.”

As to your last point of feedback, we wholeheartedly agree that the manuscript is rather lengthy. We did another pass to cut down on less relevant paragraphs as well as tables. This brought the page count down to 25 pages (from 28). When accounting for text only, our article is 14 pages long (in the MDPI/Sustainability layout). Copying the plain text into Word presents us with close to 10 pages of text in a full-width layout (default margins and spacing). We feel that any further trimming would compromise the presented information but are open for suggestions if you feel the need to cut down on additional pages.

We would like to thank you once again for your feedback and the time you spent reading our work!

Reviewer 3 Report

The paper seems scientifically sound, but I don't think I can review at as, from what I understand, there are two main problems with it:

1. It sounds like a advertisement for this tool

2. there are many tools like the one described, that have the same features, like PTV

And this sentence that justifies the reason for writing the paper is not clear at all: "In an attempt to solve and remedy the shortcomings of previous methodologies we encountered the newly released HERE Traffic API v7 [38]. The API provides access to real-  time traffic flow data, including information on the speed and jam factor for the region(s)  specified in the corresponding request. The Traffic API v7 also delivers data such as the  geometry of the road segments related to each flow information. A major advantage of this new release is the possibility to retrieve large sets of data for predefined geographical areas,  also referred to as bounding boxes or map tiles. Based on this finding, we set out once again  to answer the following research question, deduced from the original publication [37]:"

If these doubts were dispelled, the paper would be at least decent, if not good. 

Author Response

Dear reviewer,

Thank you very much for your feedback and the time you spent on reading our work.

We tried to dispel your doubts directly within the text to the best of our ability but will gladly provide additional explanations below.

In terms of advertisement, we are in no way affiliated with HERE Maps or any of the data providers referenced within this manuscript. The DERNP is also no commercial product but a transparent open source methodological approach and idea to better estimate RNP for all interested entities.

It is certainly true that many commercial software packages, such as those provided by the PTV Group, exist for similar purposes. Nonetheless, to the best of our knowledge, these software packages are mostly “closed deals” that provide working solutions for paying customers.

The DERNP, on the other hand, is supposed to fall in line with public traffic indices such as the TomTom Traffic Index in order to better account for regional differences in transportation services. The resulting coefficients provided in Table 2 can serve to efficiently incorporate RNP measurements into future academic or practical endeavors.

Nonetheless, your feedback proved very valuable to us as it delivered an additional idea for further research that we included in the respective chapter. Comparative studies should investigate differences and/or similarities between measurements of DERNP and commercial packages such as PVT. PVT (and comparable tools) might also provide a good benchmark in order to thoroughly evaluate the presented results.

We also tried to better clarify the purpose of this study by rewriting the paragraph included and highlighted within your review as follows:

“To solve and remedy these shortcomings (i.e., unidirectional routes and subjective points of origin), a solution to algorithmically generate and evaluate a large set of representative network paths is required in order to establish a general road network performance measurement. To enable such a methodology, each path within a road network requires traffic information, but historically this has led to large amounts of API transactions [10,37]. By utilizing a novel and previously unavailable feature of the HERE Traffic API [38], access to real-time traffic flow data is provided for large geographic areas within a predefined bounding box via a single request. Since each request delivers geographically referenced information on speed and jam factors for all road sections contained within the specified region, this new feature enables the efficient generation and enrichment of routable road network representations.

Based on this finding, we set out to answer the following research question, deduced from the original publication by Braun et al. [36]:

How can representative routes be generated and evaluated to reliably measure Road Network Performance and overcome limitations of contemporary RNP estimation?”

We think that this changed paragraph better serves to justify our research and hope that you agree. We are of course open to further suggestions and feedback from you in order to improve and clarify our research endeavor.

We would like to thank you once again for your feedback and the time you spent reading and thinking on our work!

Round 2

Reviewer 3 Report

Thank you for your replies, 

the paper is significant and informative, 

good luck!