Tram Expansion Effects on Reaching the City Centres—Case Study of Tampere and Braunschweig
Round 1
Reviewer 1 Report
The authors present how the quality of public transport, defined by travel (?) time, changes with the introduction of new tram lines in two cities. As the title states, this paper reads as a case study and not as an original research paper and gives an insight into the practical method(s) authors used to determine (model) one aspect of future PT Level of Service.
I have major objections to the manuscript. Firstly, it is not presented in a well-structured manner. It does not follow the journal's instructions for authors, and it is consequently hard to read and unclear. The quality of the English language is very poor, causing parts of the manuscript not intelligible. It seems that the authors haven’t spent any time proofreading their work. The abstract is obviously written in a heist, and it does a lousy job of introducing the readers to the investigation. The hypothesis is not stated in the Introduction. Most references are web pages containing publicly available statistics data and data on projects, but as this is a case study, this is expected. The scientific publications referenced in the introduction are relatively recent. However, referencing in the manuscript is not always done according to the instructions for authors. All the figures are of very poor quality and hard to interpret and understand. This is especially problematic as the authors name many districts in the analysis of their results, and their locations are not clearly visible on the maps. In addition, Figures 1 and 2 are completely unclear (due to too dark background) and would benefit from including a bus network, as the paper is considering this type of PT as well. The only table in the manuscript does not even have a caption. It seems to me that the conclusions are consistent with the arguments presented. However, the results could not be reproduced based on the described methods as the investigation is not interpreted appropriately and consistently throughout the manuscript. It is my opinion that the manuscript is not suitable for submission to this journal and should be rejected.
Due to a sheer number of specific comments, I will limit this part of my review to the Abstract and Introduction.
Line 2: The title should state “… - Case study of … “
Line 16, 17: “The study focuses on the public transport systems in the cities of Braunschweig and Tampere.” – you have said it already. Removing this sentence will allow you to use the freed-up space to better present the study.
Line 20: “time differences” – It is not clear between which specific times (travelling time)
Line 21, 22: “For this total time used -measurement, Service Area -analysis tool of ArcGIS Pro - software is used.” The abstract should explain in more detail the steps the authors have taken to analyse the areas. Mentioning the software used in the analysis is not enough. Also, the authors should give a short explanation of the results at the end of the abstract.
Line 28, 29: “Even in cities the car users can be very high” – I believe authors have thought the share of private cars in urban modal split can be very high. The percentages given in the literature should emphasize this statement.
Line 29: Authors should provide more information on the type of emissions, it is unclear.
Line 35: Authors should correct the referencing/punctuation.
Line 40: “…that are typically measured with passenger surveys.” - If it is a survey result, the quality is said to be defined or evaluated and not measured.
Line 42: Authors should correct the referencing/punctuation.
Line 45: Authors should present the country in brackets behind the city’s name.
Line 46: “… the public transport network viewpoint.” - It is unclear whose viewpoint is this, passengers, or the networks manager?
Line 51-58: This last paragraph mostly repeats the information from predeceasing one. Merging the last two paragraphs of the Introduction could result in sufficient information on the investigation location. The Introduction should end with the research aim/hypothesis, a brief mention of the methods used, and the contribution of the expected results.
Author Response
Please see attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
This paper investigated the impact of tram lines on travel time using two cities. The paper is well written and the study is interesting. My comments to further improve the paper are as follows:
It is not very clear how the findings in the paper can be used or what the readers can learn from the study.
As has been pointed out by the authors, this study only assessed the impact of tram lines on travel time. Is it possible to include any travel costs (e.g., ticket fares) in the assessment?
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 3 Report
This study seeks to compare and analyze the effects of tram expansion projects in Tampere, Finland, and Braunschweig, Germany, from the perspective of the public transportation network. These cities were selected because their population sizes and proportions of public transportation are comparable. The analyses focused on how the extension of tramlines affects the accessibility of city centers. This was determined by calculating the time differences between the current and future networks for both cities under consideration.
The topic of this paper is interesting, and I believe that further investigations into this matter may provide a reference for tram expansion projects worldwide. However, I would recommend modifying the following points:
- The drawings in Figure 1, Figure 2, Figure 5, and Figure 6 are made with colors and a dark background. If the publication is going to be black and white, can the authors consider this issue by modifying the drawings, lines, and background? Please check this issue for all figures and tables.
- Line 35: the period “.” before [3] needs to be removed.
- Line 42: the citation of [4]; [5] should be combined as [4, 5], and the period “.” should also be moved after. This issue should be fixed all over the manuscript, like in line 241, etc.
- The conclusion section (the first three paragraphs) looks like a discussion. The authors need to redo this section to provide solid conclusions regarding their results.
- Did the author consider comparing their results with previous studies and projects?
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Major changes to the manuscript are required. Please see specific comments.
Line 27-33: Please be more precise and more consistent in presenting (you jump from one information to another without obvious connection) and proofread your manuscript again. My proposition for improvement of this specific section: “In rural areas, people are usually not well connected by public transport (PT) and are therefore often dependent on their cars for daily migrations. Here, up to 70 % of all trips are made by personal car. In the metropolitan areas, PT, bicycling, and walking are increasingly common. Although people in large cities drive fewer cars than those in rural areas, car use here can also be high because many people within the cities are poorly connected by PT. On average, metropolis residents travel 14, and residents of small towns travel 26 km per day by car [1, 2].”
To make the manuscript easier to read, please use the abbreviation PT instead of public transport (after its first mention). You have used it in the abstract (line 14) and began to use it sporadically after line 48. Please correct this throughout the entire manuscript.
Line 40 should state: … and ITS quality characteristics are different…
Line 41 should state: …cities by PT’s Quality of Service…
Lines 47-61: Please re-write this paragraph as follows: “This research presents a case study of two cities, Tampere (Finland) and Braunschweig (Germany), which have successfully increased PT ridership during the last years. They are of similar size in terms of population and have a similar modal share of PT. The aim is to analyse and compare the effects of the tram network’s expansion projects from the tram passenger’s viewpoint i.e., how passenger accessibility changes when a part of the PT network is modified. The accessibility of the two city centres is analysed by modelling the travel time taken to reach the city centre from other areas. The central city area is comparable in both cities, as both work and leisure destinations are located there, and both networks are mainly built around these areas as a hub. As a hypothesis, it is expected that even though the tram extensions will reduce the time taken to reach the city centres within the tram corridors, there may be areas that will have a reduction in their Quality of Service, as the tram extensions may also remove some existing direct bus lines and replace them with connecting lines to the tram network, thus causing transfers, and therefore, increasing travel time.”
Ch 2. The investigation area should be moved to the beginning of the new Ch 3. Materials and methods in a new sub-chapter 3.1.
Lines 63-64: Remove this sentence.
Line 80: Remove the dot from the beginning of the first sentence.
Line 99 should state: Trams operating on the first phase of the tramway infrastructure…
Lines 103-105: Please move the sentences describing Phase 2 in/after current line 90.
Lines 108-110: Move the sentences describing the bus system to line 80: “Until now, public transport in Tampere has been dominated by bus. In Tampere there are eight different bus companies, which serve a network of about 60 lines. Nearly all lines connect the suburbs with the city centre [20]. The bus companies serve a network of approximately 18 million km per year in the Tampere region [21].” … and then continue to describe the tram extensions; “In 2016, the City Council of Tampere decided to build the first phase (red in figure 1) of the tramway infrastructure with the depot and lines from Hervanta and the TAYS hospital region to the city.” and then continue with “This new tramway in Tampere replaced a direct bus connection between city centre and Hervanta, and few bus lines became tram-connecting lines, i.e. the number of bus connections decreased.”
Line 113-115: Remove the sentence “This has the advantage that the average speed on these routes is significantly increased and the travel comfort for the passengers increase”.
Line 118: Please be consistent in writing numerals, do not write “There are six tram lines and 37 bus lines” but “There are 6 tram lines and 37 bus lines” or “There are six tram lines and thirty-seven bus lines”. This should be corrected throughout the manuscript (etc. in line 120: between four and 14 kilometres.)
Line 119 should state: “The 6 existing tram lines are currently 58.7 km long.”
Line 123: “211 persons” – replace persons with passengers (or are you counting the driver as well?)
Lines 92-95 and 123-124: When describing the trams in both cities please use the same parameters: manufacturer, capacity, speed, length, gauge, number of doors, length, bi-directional or uni-directional tram, and floor height… if you do not have all the above-mentioned data for both cities, present the common data you do have.
Line 126-127: Please write day – month – year as in the rest of your manuscript
Line 129-130 should state: “This decision allowed the detailed planning of the extension to continue.”
Line 130 should state: “As given in the report…”
Line 133: remove “of the BSVG“ and instead write “The BSGV’s network plan for 2030 foresees for bus lines…”
Lines 134-136: remove the sentence ”This has the advantage that the average speed on these routes will be significantly increased and the travel comfort for passengers will increase.”
Lines 140-145: This part of the manuscript describes the passenger volumes, but only qualitatively, and only for the German case. It does not contribute to the manuscript at this stage. Remove.
Line 149: Move Ch 3. Theoretical background after the Ch 1. Introduction. Start this new Ch 2. with current lines 176-178: For the theoretical background, it is necessary to analyse how to compare the PT in different cities. Two cities with the same population, area size, and a number of stops can still have very different access PT. Continue with the text from current lines 187-208. Then continue with current lines 179-181: “As already mentioned, PT in Tampere and Braunschweig will be provided by buses and trams. Some bus lines will be discontinued, as they are replaced by new tram lines.” Then continue with current lines 150-…
Lines 150-151 should state: “As in both analysed cities individual bus lines will be replaced by the tram, it is important to present the advantages of a tram over a bus. Two main advantages are capacity and speed.”
Lines 156-157: The segregated tram is affected by other road users only at intersections. It should read: “These two track formations also increase the punctuality of the tram because the independent tram is not at all affected by other road users and segregated tram is affected by other road users only at crossings and intersections.”
Line 158: Replace “junction” with “intersection”.
Line 159: “…, and a bus…”
Lines 160-162: Something is wrong with these two sentences, should they be joined, somehow?
Line 166: What do you mean by “interchange”? You talk about transfers later. Should this state transfer instead?
Line 173-175: It will be better to use this sentence in the abstract or in the introduction, remove it from this part of the manuscript.
Lines 181-186: remove the text “The network design of the new tram lines are partially completed in both cities. For the design of new networks, the planning of stops, the guarantee of a minimum travel time, and a sufficient minimum connection must be taken into account. The economic operation, the creation of an attractive transport offer for the passengers as well as the assurance of a sufficient operating quality as objectives of the line formations must 185 also be considered [30].” It is not relevant for the investigation.
Line 192: correct the referencing style to “according to [ ]”
Line 196: should state “… in Japan where this ratio is achieved.”
In this chapter, you should add a short theoretical explanation of PT travel time calculation/modelling procedures and present tram travel time influential factors more systematically.
Line 209: Ch 4. Methodology should be Ch 3. Materials and methods. Start with 3.1 Investigation area
Line 211-212: Measuring - Please consider a different word here, for measurement is a process of determining how large or small a physical quantity is as compared to a basic reference quantity of the same kind. It is not wrong, but it is misleading as it is common to do measurements on-field. Since you have compiled your data from secondary sources, maybe this sentence should state: “We have done this by comparing the travel time on the current network (using data given in timetables) and the travel time on the planned future network (modelled by using certain presumptions) in different case areas for both cities.” Modify the abstract accordingly.
Lines 217-218: ”… containing all the necessary information regarding our analysis” here please list all the data you have extracted from GTFS-datasets after a colon.
Lines 233-237: Here you talk only about driving time (running time). What about stop and intersection dwell times that need to be incorporated to predict the travel time?
Line 250: areaa..
Line 250-252: Remove “, where we measured the changes in travel time, We did not have any one specific stop or point, where the time to travel is measured, but an area instead.”
Line 252: Travel time, not time to travel, be consistent.
Line 253-254, 279: Instead of reached, reachability, use accessed, accessibility as in the other parts of your manuscript, be consistent.
Lines 281-284: This part you have added does not fit very well here. Maybe you should move it after completed additions to the text in current lines 217-218.
Line 296: This chapter should be renamed Results.
Lines 297-300: Sentences are written awkwardly and do not give proper input to this part of the manuscript: “In this section the analysis of the tram networks in Tampere and Braunschweig are presented.” You present the results of the travel time differences i.e., accessibility of three areas before and after the tram network expansion. You do not analyse other characteristics of the networks. “Additionally, an overview of the changes and their reasons are given.” Reasons should be placed in the new chapter Discussion, please present here the results only without commenting on the possible reasons that led to them. ”Table 1 depicts how the new network changes the accessibility of target areas and how many people are affected by the change.” The network is not a living creature, it cannot change anything. However, Table 1 depicts how the introduction of new tram extensions changes the accessibility of target areas and the number of people affected by the change.
Line 301: Case areas or target areas? Choose one and stick with it.
Line 303: The network is not going anywhere; the travel time is shorter.
Lines 304-306: Please give the percentages of citizens instead of the “majority”, “14 000” and “56000”. Give the same presentation for Braunschweig later.
Line 314: If Tampere did not have a tram system before, what is the old PT network you are referring to? Please state bus, as there are great differences between these two systems (you have stated that yourself). Same for line 321, 323, 328, etc.
Lie 319: There is no “Teisko” on the map. Please add, by hand in image processing software, if necessary, the Toponyms you are referring to in the text to all the Figures. In general, Figures 4, 5, and 6 are still of poor quality and completely unreadable.
Line 328: Journey time, change to travel time.
Line 329: Please add a full stop after “area and city centre” and continue with a new sentence.
Line 331: “However, some direct lines still exist as well, however the service frequency has reduced.” Remove either the first or the second however and rewrite the sentence.
Lines 372-374: Remove.
Line 381: Remove.
Line 410: Remove.
Line 452: This Ch should be renamed to Discussion.
Line 453: Tram transport system.
Lines 453-459: Seems to me that this text fits better with the Conclusions.
Lines 468-474: Remove, this has nothing to do with your investigation.
Line 475: There is no need to start the sentence with “However… “, remove it.
Line 475-481: This paragraph should not stand under Tampere subchapter; this is a general remark for both cities and should be placed in the Conclusions.
Line 484-485: First two sentences - You cannot conclude this from your results, especially since the new lines are not yet built? Remove.
Line 488: First sentence, remove it, you have said it a few times already.
Line 509: Finish the sentence with: … on city centre accessibility.
Line 508: Explain here in more words what you precisely mean by ‘network effect’.
Line 510: Effect on accessibility?
Line 512: Replace “tramline developed” with “tram track constructed”
Lines 523-526: “…as the area only served via a segregated tram network will be larger and the same benefits would at least be applied to those catchment areas.” This is completely unclear, proofread, and write shorter sentences.
Line 529: What method? Analysis method as the one you have used in the investigation? It is not clear.
Line 532: travel time
Line 533: Place a full stop after “level of service”.
Line 533, 535, 537: In the previous text, you have referred to Quality of Service. Be consistent in the nomenclature.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 3
Reviewer 1 Report
The manuscript is now much easier to read, but it still needs a considerable amount of interventions to present the case study more clearer. Further changes are required (please see specific comments), together with detailed proofreading by a native English speaker.
Line 16: change “from the public transport network viewpoint“ to „from the public transport network users' viewpoint.“
Lines 20-21: change “For this total travel time used -measurement, Service Area -analysis tool of ArcGIS Pro - was used…” to “For this total travel time, ArcGIS Pro Service Area Tool was used…”
Lines 21-22: change “The results vary depending on not only due to the tram expansion, but also due to bus network changes of the connecting network.“ to “The results vary due to the tram expansion and changes in the existing bus network.”
Lines 74-76: Sentence “These two track formations also increase the punctuality of the tram because it is not affected by other road users only at crossings and intersections (segregated track formations).” is still poorly written, change to “These two track formations also increase the punctuality of the tram because the independent tram is not at all affected by other road users and segregated tram is affected by other road users only at crossings and intersections.”
Line 110: “…with a medium PT frequency”, same for line 112
Lines 113-114: correct to “…the only way to define the accessibility of a PT service is to measure the proximity to a PT service [15].”
Lines 133 – 134, 141: add “network” after “tramway”
Line 143: Add “lines” after “tramway”
Lines 142-143: 18 million km per year – in what period, before or after the 1st phase of tram network construction?
Line 148: change to “…of trams will run on segregated track…”
Lines 137-152: Reorder the sentences in this chapter – first present the data for the bus: “Until now, PT in Tampere has been dominated by bus. There are eight different bus companies in Tampere, which serve a network of about 60 lines. Nearly all lines connect the suburbs with the city centre [27]. The bus companies serve a network of approximately 18 million km per year in the Tampere region [25]., In 2016, the City Council of Tampere …”
Line 162: change “Part 2 of the Tampere tram covers the section from Pyynikintori, where the current...” to “Second phase of the Tampere tram network covers the section from Pyynikintori, where the first...”
Line 163: change “western” to “secondly”
Line 164-165: remove the sentence “As already mentioned the aim is to build the line in the years 2021-2024.”
Lines 168-169: remove the sentence “The Braunschweiger Verkehrs GmbH (BSVG) is the transport company of the city of Braunschweig.”, you have stated this earlier. Begin the section with “There are 6 tram lines and 37 bus lines in the city of Braunschweig [31].” Keep the line in the same paragraph and continue: “The 6 existing tram lines are currently 58.7 km long…”
Line 192: please state: Current and planned tram network in Braunschweig, Germany
Lines 194 – 197: Sentence: “We do this by calculating the travel time between the current network (using timetable data) and the planned future network (modelled by development plans for Braunscweig) in different case areas for both analysed cities.” If I have understood correctly, Tamperes' first phase is finished and under operation. It would be better to change the term “current network” to “old network” when you refer to Tampere old bus network, use the term “current network” when talking about Tampere first phase and Braunschweig existing tram network, and “planned network” for those to be constructed. The sentence should state: “We did this by calculating the differences between travel time on the old network and the current network in Tampere, and planned future network Braunschweig, in different case areas for both analysed cities.”
Line 201 and 207: use “current” instead of “present”, as you have used this term in the figure 2
Line 201: add “…General Transit Feed Specification (GTFS) datasets…”
Line 288: planned networks – you have used plural. Does this mean that you have analysed the second phase in Tampere? If not, state “planned network”.
Lines 221-225: “waiting times on stops and interchanges”. Please state the assumptions on dwell time durations you have incorporated in the models.
Line 261-262: change “We wanted to know the difference between how the study areas could be accessed in the morning.” to “We wanted to calculate the difference between the accessibility of the study areas in the morning period.”
Line 264: selected
Line 279: what is YKR?
Line 276-273: Would it be possible to present population density maps?
Line 429: replace “go” with “run”
Line 455: replace “levels of service” with “Quality of Service”
Lines 452-469: Please use the future tense when discussing the benefits of planned network extension.
Line 476: remove “in PT”
Line 480: remove “than previously”
Line 483: remove “for example”
Line 488: state “If the area served…”
Lines 492-498: this part could better fit in the Discussion
Lines 503-518: Investigation limitations and further research should be stated in the Discussion.Line 500: tramway network
Line 506: western extension – add that this is a second phase
Line 532: remove Declare conflicts of interest or state
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 4
Reviewer 1 Report
The authors have successfully incorporated the requested changes and additional information in their manuscript. I believe the paper is now suitable for publication, after minor style corrections that can be addressed at a later stage by the journal's internal staff.
