Study on Road Friction Database for Traffic Safety: Construction of a Road Friction-Measuring Device
, Tetsunori Haraguchi 1,2,3,*, Tetsuya Kaneko 4, Minoru Nishio 5 and Atsushi Watanabe 2
Round 1
Reviewer 1 Report
This study seems to be very practical to estimate the friction coefficient under vehicle driving condition so that it can replace the cost-ineffective bench test. Main topic is interesting for this journal but several issues should be cleared before considering it for publication.
[1] Few explains was for MF identification method.
[2] There were also few explanations for the measured data in chapter 1 and 2. [3] Authors modified the estimation of friction coefficient in a low slip area but the criterion to select the reasonable modification area was vague.
[4] Authors claimed the advantage of the proposed method was to develop a method for continuously measuring the friction characteristics of ordinary roads. But, you did not show that in current version. Additional example may be required for verify it.
[5] Authors may use the existing formulations about the identification of the friction coefficient. Is it necessary to verify again at chapter 2.2?
Author Response
Thank you for your review. We examine the contents carefully and reply as the attached document.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript presents a friction coefficient measurement trailer that is able to measure at three different slip ratios at the same time. The idea fits perfectly the aim of the journal. Additionally, the device can suppose a great advance in the field of the pavement skid resistance.
With regard to the quality of the paper, some major points must be indicated.
First of all, at first sight, there is something that seems unusual in scientific papers: the low number of references. Generally, scientific research article in international journals include a larger quantity of cites during the text. This article only employs 6 references. 4 of them (66%) are from the authors. This can be understood because previous own works are commented, but more references of other authors must be inserted. Although some ideas can be known, it is usual to support those ideas by citing other authors. Additionally, from those 4 authors’ own references, 3 of them are in Japanese, reducing the possibility the dissemination of that knowledge. One of the rest of references is the one about the magic formula. Therefore, some places where references can be introduced are commented. Some works are suggested in some points. For example:
At the first sentence of the Introduction, when indicating the main factors affecting the friction coefficient, a more clear idea should be given. Factors affecting friction are the tyre-road contact interface (Road surface texture, tyre rubber type, etc.), tyre characteristics, the operating conditions and environmental conditions (Kane et al. 2019). Perhaps, a table as the one shown in Perez-Acebo et al. 2019 and Perez-Acebo et al. 2020 would be adequate. These references would be convenient in this point.
In the same first paragraph, when introducing the reference [1], the idea of the importance of the road friction on road safety should be expanded. For example, it could be said that the skid resistance or friction is one of the most important characteristics of the pavements. It is the friction resistance that is generated between the vehicle tire and the pavement surface, which allows drivers to manoeuvre and guide their vehicle safely, in both longitudinal and transversal directions. Although road crashes are said to be due to multiple factor, relationships between accidents and pavement surface characteristics (friction and texture) have been established empirically (Walman and Astrom 2001;Nafaji et al. 2017, Nafaji et al. 2019).
In the sentence “In particular, this value is important for road maintenance”, I would rewrite it like “In particular, this value is fundamental for pavement management, as many road administrations include this value in their pavement management systems (AASHTO 2012). Additionally, due to the importance of the friction value, many researchers tried to predict the friction coefficient in roads (D’Apuzzo and Festa 2004, D’Apuzzo and Nicolasi 2008, Echaveguren et al. 2010, Echaveguren and Solminhac 2011, Perez-Acebo et al. 2022). In fact, these ideas contribute to underline the importance of the pavement friction. Then, the sentence starting with “On the other hand, among…” should be placed in a new paragraph.
In page 2, when indicating that the ABS system is mandatory for ordinary vehicles in Japan, the law indicating this point should be cited.
Another important point to be mentioned about the paper is the precedence of some figures. It is not clear who are the authors. For example, Figure 1. It is said that it “shows the results of mu-s characteristics measured using various tires under various road surface conditions. Were measures conducted by the authors or those data were extracted from somewhere? In the case of the second possibility, the references should be given. If authors conducted the measurements, it is necessary to clearly indicate it too. Similarly, experiments shown in Figure 3 were made by authors? The same can be applied to Figure 4 and Figure 5. Then, from Figure 6 onward, it is clear that the tests were conducted by authors.
Moreover, another major point is that Equation (2) is called Magic Formula or MF in the paper. This idea can be commented when presenting it, that is correct. However, when referring to it along the paper, it is more correct to refer to as Equation (2). This is why Equations are numbered in scientific papers. For example, before Equation (2), before Equation (3), it should be “…is obtaining differentiating Equation (2) with respect to s”. The same can be applied before presenting Equation (5). Other places: After Figure 3, after Figure 4 (4 times), after Figure 16 (twice), in the title of Figure 19, and in the conclusions.
Finally, it must be indicated that the title can disorient the aim of the paper. When reading the title I was thinking about managing friction data from databases for traffic safety. However, the aim of the paper is the second part of the title: the development of a new friction measuring device. Therefore, authors are suggested to modify the title, perhaps reducing it to the second part.
Other minor points:
At the end of page 1, define ABS the first time it is mentioned, although it can be known for readers.
Place Figure 1 just after commenting it for the first time.
Equation (2). After presenting it, define the variable. Although “a”, “b”, and “c” are just coefficient, indicate it clearly, and if they have a specific name, mention it.
After Figure 7. The total weight is less than 750 kg. As it is weight, the unit should be kg. Include a space between the number and the units.
Section 3.2. Include the main measures of the 125R12-62S tyre. Additionally, compare those values with values of tyres on other friction measuring devices. References for those devices should be included.
Section 3.3. Include load values in other tests and compare them with the selected ones.
Section 4.1. The slip ratios of the proposed devices measure are at 0.954%, 7.057%, ad 17.23%. Perhaps, the slip ratio of 0.9 is very low compared to the values employed in Figure 1. Comment this point.
Figure 16. Include the exact names of the denomination of the materials presented. For example, for material in b), is it a discontinuous hot mix asphalt (of BBTM type) or a Porous Asphalt (PA)? Similarly for material in a).
AASHTO (2012). Pavement management guide. 2nd Edition. American Association of State Highway and Transportation Officials. Washington, DC.
D’Apuzzo and Festa (2004). The evaluation of the evolution of road surface friction: a case study in Naples’ district. In 3rd Eurasphalt and Eurobitumen Congress, 112-14 May 2004. Viena, Austria. Breukelen, The Netherlands: Foundation Eurasphalt, 1146-1160.
D’Apuzzo and Nicolasi (2008). An energy based approach to predict skid resistance progression. In 87th TRB Annual Meeting, 1317 January 2008, Washington, Paper 08-0249.
Echaveguren et al. (2010). Long-term behaviour model of skid resistance for asphalt roadway surfaces. Canadian Journal of Civil Engineering, 37, 719-727.
Echaveguren and Solminhac (2011). Seasonal variability of skid resistance in paved roadways. Proceedings of the Institution of Civil Engineers – Transport, 164 (TR1), 23-32.
Kane et al. (2019). Contribution to pavement friction modelling: an introduction of the wetting effect. International Journal of Pavement Engineering, 20 (8), 965-978.
Nafaji et al. (2017). Linking roadway crashes and ire-pavement friction: A case study. International Journal of Pavement Engineering, 18(2), 119-127.
Nafaji et al. (2019). Pavement friction management-artificial neural network approach. International Journal of Pavement Engineering, 20 (2), 125-135.
Perez-Acebo et al. (2019). Skid resistance prediction for new two-lane roads. Proceedings of the Institution of Civil Engineers – Transport, 172 (5), 264-273.
Perez-Acebo et al. (2020). Skid resistance prediction model for an entire road network. Construction and Building Materials, 262, 120041.
Perez-Acebo et al. (2022). A simplified skid resistance predicting model for a freeway network to be used in a pavement management system. International Journal of Pavement Engineering, doi: 10.1080/10298436.2021.2020266
Wallman and Astrom (2001). Friction measurement methods and the correlation between road friction and traffic safety: A literature review. VTI Meddelande 911A, Swedish National Road and Transport Research Institute, Linköping, Sweden.
Author Response
Thank you for your high evaluation of our research results. We examine the contents carefully and reply as the attached document.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Most of reviwer's claimed issue were solved in the revised version. After editing English, I recommended this job for publication.
Author Response
Thank you very much for your review. We reply as follows. In the manuscript, previous changes are shown in red, current changes are shown in blue.
(Comment 1) English language and style are fine/minor spell check required. Most of reviwer's claimed issue were solved in the revised version. After editing English, I recommended this job for publication.
(Response 1) English was corrected by a Native English speaker.
Reviewer 2 Report
Most of the comments were conveniently addressed. Nevertheless, some of them need additional information. Additionally, some references are not correctly introduced.
Author Response
Thank you very much for your review. We examine the contents carefully and reply as follows. In the manuscript, previous changes are shown in red, current changes are shown in blue.
(Comment 1) English language and style are fine/minor spell check required.
(Response 1) English was corrected by a Native English speaker.
(Comment 2) Does the introduction provide sufficient background and include all relevant references? Can be improved.
(Response 2) Introduction was reviewed and added. Five references were newly added and two references.
(Comment 3) Are the methods adequately described? Some of them need additional information. Can be improved.
(Response 3) The text has been revised and added.
(Comment 4) Are the results clearly presented? Some of them need additional information. Can be improved.
(Response 4) The text has been revised and added.
(Comment 5) Some references are not correctly introduced.
(Response 5) Five references were newly added and two references were deleted as a result of the review of references. Errors were corrected by reviewing References.
Round 3
Reviewer 2 Report
I must apologize. After reading the authors’ answer, I noticed that I have placed wrongly the comments and authors received the comments for the editors and vice versa. Consequently, authors were not aware of my previous comments. However, as they reviewed the paper with an English-speaking native, some points were corrected.
I include the points from the previous review that were not modified.
With regard to the first sentence, I think that the effect of environmental factors of friction coefficient must be introduced. Therefore, the sentence must be completed with “, and environmental conditions (Kane et al. 2019) [reference 12]. Thus, all the affecting factors are mentioned.
When including the reference “(AASHTO 2012)”, it must be treated as a reference. Hence, it must be included a number between square parentheses, [xx], and then, incorporate it to the reference list.
Similarly, in the 2nd page, when citing the law that include the ABS as a compulsory component in vehicles, it is just a new reference. Include a number, [xx], and the law or laws, in the reference list.
When indicating to include the main measures of the 125R12-62S tyre, I was not saying to include the reasons for choosing it. I just wanted the measures of the tyre! I can look for it in Google, but I think it is more appropriate if the paper include this information: diameter, width, pressure, etc.
Similarly, when indicating the loads of other tests, I am not discussing the reasons for choosing those values. It was just to include in the text the values of other tests, just for comparison. It would be adequate to compare it with other main friction measurement devices. People would like to have a quick comparison with other devices. For help, you have some values of the most widely employed measurement devices in Europe:
https://cordis.europa.eu/project/id/217920/reporting
It is logical to include other devices’ data (load, wheel, and slip ratios).
Reference [1] is not correctly displayed because all the authors of the documents must be included.
Author Response
Thank you for your review comments. Based on the discussion between the authors, we would like to reply as attached.
Author Response File: Author Response.pdf
Round 4
Reviewer 2 Report
With regard to the first point, I completely understand the direction of this research. Authors are developing a device for continuously measure friction characteristics (μ-s characteristics). As you indicate, environmental factors are important in skid resistance measurements. It is true that your research is not directly related to this point, but it would be more convenient to indicate all the factors affecting the measured values. Just a sentence at the beginning of a paper would not affect the aim of the paper and the sense would be perfectly understood by readers. If you want to leave that sentence uncompleted, it is up to you.
Regarding the inclusion of the references, once you mention them, they must be included in the reference list. Therefore, the reference AASHTO 2012 and the ones about the ABS as a compulsory element in Japanese laws must be included, even if they are in Japanese. Authors from other countries cite national standards even if they are not in English.
The rest of the paper is correct.
