The Effects of Signal System and Traffic Flow on the Sound Level
Round 1
Reviewer 1 Report
Dear Authors,
The manuscript is well written and understandable. Some minor errors are found which are listed below and some suggestions are made as follows:
Introduction: First sentence
It is a statement which is not cited wo I believe it should read: Hong Kong is an economic city with probably the highest traffic intensity ...
4th line of the same paragraph: .. Traffic noise and signal-controlled systems are ...
7th line of the same paragraph: et. al. is written without a point at et, i.e. "et al.". It comes from latine: et alii ("et" means "and"). This is throughout the text.
Page 2: In the middle of the page.
Lmax and Lmin, are these A-weighted levels? It is written that LAeq(1) was recorded and Lmax and Lmin, however, not stated if these levels also measured with an A-weighting. Suggestion: write LA,min and LA,max.
A vehicular speed is given in km/h. On page 3 the vehicle speed is given in km/hr. It is suggested to write speed in km/h throughout the text, which is common writing.
Unter section 3.
The sound pressure level (Leq) should be written as (LA,eq). This is throughout the text and all formulae.
Page 3:
The background sound levels are given in dB and the sound pressure level in dB(A). It is suggested to write all sound pressure level following ISO regulations in dB indicating that it is an A-weighted sound pressure level, e.g. LA,eq. = 66.4 dB.
In the text a sound pressure level Leq(1sec) and (L10) is presented without introduction. It is common that for example, the L1 is the level that was exceeded only during 1% of the measurement time. It is therefore a level peak measure. The L10 is corresponding to the level that is exceeded during 10% of a measurement time.
This will be explained later in the chapter Conclusion!
In general, the Leq is not suitable for recording all situations. If, for example, individual very loud events occur, this is not apparent from the averaging level. In these cases, the peak level Lmax is better as a description measure. If you wanted to specify an averaging level, you should not use Leq.
So it is not clear what Leq(1 sec) and what L10 are and why these measures have been chosen for this study.
In the conclusion part it is missing what effect a stop-and-go event has and if one can quantify. The summary: "Therefore, optimizing traffic light settings can be a useful means of alleviating traffic noise pollution..." is well known knowledge and is a predictable and expected result even without extensive measurements. For example there is a German Directive (RLS-90) that offers a correction in dB for increased interference effect of light sign-controlled crossings and confluences. Therefore, it is important to know for forecasting reasons what the impact of a controlled traffic light setting would be.
All Figures and illustrations are of very poor quality and very fuzzy. It is difficult to see details. It is suggested to remake the Figures.
Overall, a significant result is missing. No scientific contribution is made. I propose that the study be revised in order to be able to present new findings.
Author Response
See the Pdf file attached, which contains our responses and revised ver.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript presents results of trafic noise road measurements in Hong Kong with and without traffic signals. It includes many quantitative data for van and coach movement for various traffic flow conditions and scenarios and studies the effect of signal system and traqfic flow on the noise level.
To my mind, the discussion of the experimental data obtained should be significantly improved. At present it is qualitative in character (a higher peak sound level; the higher the van/coach speed is, the higher the peak sound level is measured; the peak ... is wider and jumps down sharply; a longer time; takes longer to decay sharply; the curve slopes are deeper etc.). These "raw experimental data," as is written in Conclusion, after corresponding processing, can provide qualitative data.
The same is true for Conclusion (the sound level ... is higher and the traffic flow is lower; the sound level is higher; the traffic flow is high; may be slightly lower).
I cannot recomend this manuscript for publication in its present form. The authors claim to study first the effect of signal system and traqfic flow on the noise level, but did not support their claim with their results given in the manuscript, though they have obtained many experimental data.
However, in Conclusion, this effect is described only qualitatively ()
L10 and Leq noise levels
Author Response
See the Pdf file attached, which contains our responses and revised ver.
Author Response File: Author Response.pdf
Reviewer 3 Report
I am a bit confused about the goodness of the paper, and, for this reason, I’m expecting serious improvements by the authors. However, the paper investigates traffic noise related to signals, but I sincerely did not understand the relation the authors find between the noise measurements and the signals conclusions. While the subject is deserving attentions and study, the present work needs to improve analysis, details about measurements, abstract, introduction, references focusing on readers’ understanding.
- “the present research is the first study about the effect of traffic signal on the noise level of moving vehicles” See the works of De Coensel in this regards.
- Abstract should be longer and explain a bit more.
- Introduction needs deep improvements from two point of view: the references are too Asian centric and should be more world oriented, and the last part of introduction should better introduce the work. Thus, please add few lines more explaining what, why and how the work will do, and please consider to add the following suggested in the correct placements. In the following the authors will find a list of suggested paper that will add value to the background and refences of the current paper:
Few lines can be useful to just mention the other important noise sources and their effects on health: “Railway traffic (Licitra, Gaetano, et al. "Annoyance evaluation due to overall railway noise and vibration in Pisa urban areas." Science of the total environment 568 (2016): 1315-1325. Bunn, Fernando, and Paulo Henrique Trombetta Zannin. "Assessment of railway noise in an urban setting." Applied Acoustics 104 (2016): 16-23) represent the second most impacting noise source affecting human modern life style (Licitra, Gaetano, et al. "A novel method to determine multiexposure priority indices tested for Pisa action plan." Applied acoustics 72.8 (2011): 505-510.), after road traffic (Cueto, J. L., Petrovici, A. M., Hernández, R., & Fernández, F. (2017). Analysis of the Impact of Bus Signal Priority on Urban Noise. Acta Acustica united with Acustica, 103(4), 561-573.Morley, D. W., et al. "International scale implementation of the CNOSSOS-EU road traffic noise prediction model for epidemiological studies." Environmental pollution 206 (2015): 332-341. Ruiz-Padillo, Alejandro, et al. "Selection of suitable alternatives to reduce the environmental impact of road traffic noise using a fuzzy multi-criteria decision model." Environmental Impact Assessment Review 61 (2016): 8-18; Licitra, Gaetano, et al. "Performance assessment of low-noise road surfaces in the leopoldo project: comparison and validation of different measurement methods." Coatings 5.1 (2015): 3-25; Bianco, Francesco, et al. "Stabilization of a pu Sensor Mounted on a Vehicle for Measuring the Acoustic Impedance of Road Surfaces." Sensors 20.5 (2020): 1239.), but before airports (Gagliardi, Paolo, et al. "A statistical evaluation on flight operational characteristics affecting aircraft noise during take-off." Applied acoustics 134 (2018): 8-15. Iglesias-Merchan, Carlos, Luis Diaz-Balteiro, and Mario Soliño. "Transportation planning and quiet natural areas preservation: Aircraft overflights noise assessment in a National Park." Transportation Research Part D: Transport and Environment 41 (2015): 1-12.), industries and wind turbines (Fredianelli, Luca, et al. "Analytical assessment of wind turbine noise impact at receiver by means of residual noise determination without the wind farm shutdown." Noise Control Engineering Journal 65.5 (2017): 417-433.; Michaud, David S., et al. "Exposure to wind turbine noise: Perceptual responses and reported health effects." The Journal of the Acoustical Society of America 139.3 (2016): 1443-1454.) and port activities (Bernardini, Marco, et al. "Noise assessment of small vessels for action planning in canal cities." Environments 6.3 (2019): 31; Bolognese, Matteo, et al. "Port Noise and Complaints in the North Tyrrhenian Sea and Framework for Remediation." Environments 7.2 (2020): 17; Fredianelli, Luca, et al. "Pass-by Characterization of Noise Emitted by Different Categories of Seagoing Ships in Ports." Sustainability 12.5 (2020): 1740.).
Sleep disorders with awakenings (Muzet A. Environmental noise, sleep and health. Sleep Med Rev 2007; 11: 135–42.), learning impairment (Zacarías, F. F., Molina, R. H., Ancela, J. L. C., López, S. L., & Ojembarrena, A. A. (2013). Noise exposure in preterm infants treated with respiratory support using neonatal helmets. Acta Acustica united with Acustica, 99(4), 590-597..), hypertension ischemic heart disease (Dratva, J., et al. (2012). “Transportation noise and blood pressure in a population‐based sample of adults.” Environmental Health Perspectives, 120(1): 50–55. Babisch, W., Beule, B., Schust, M., Kersten, N., Ising, H., ‘Traffic noise and risk of myocardial infarction’, Epidemiology, 16, 2005, pp. 33–40. ) and especially annoyance (Miedema HME, Oudshoorn CGM. Annoyance from transportation noise: relationships with exposure metrics DNL and DENL and their confidence intervals. Environ Health Perspect 2001; 109: 409–16.), are the most common negative health effect related to prolonged exposition.”
I personally think that this will be sufficient to help compensating the lack of a proper introduction and bibliography in the present form of the paper.
- Reported figures have bad quality. Improve it.
- In chapter 2: No need of reporting brands of instrument, instead specify the class of sound level meter. Also, in the text is important to report information only remanded to the table (mic height, and so on.).
- How many passages for each type have been measured and analyzed?
- Figure 5 and all the similar, what is the height of measurements reported?
- I failed to understand how the authors make use of the 4 simultaneous measurements at different height and distance from a passage. Please explain it.
- Why only limiting to 2 type of vehicles? The possibilities are to mention it also in the title, thus limiting the value of the work, or, what I suggest, is to increase the value by analyzing and reporting more vehicle type, such as normal cars.
Author Response
See the Pdf file attached, which contains our responses and revised ver.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The authods significantly improved the manuscript and I recommend it for publicalion.
Reviewer 3 Report
The authors followed my suggestions and the paper is ready for being published
