The Potential Carrying of Bicycles Inside the Train Carriage: An Experimental Pilot Study Based on Valparaíso Metro, Chile

Abstract

This study analyses the potential carrying of bicycles inside a train carriage. To this end, an experimental methodology based on observation and experimentation is implemented. The survey is conducted on the metro system in Valparaíso, Chile, highlighting the importance of intermodality between bicycles and trains. It identifies that the current capacity of the carriages is not adequate to ensure safety and efficiency during boarding and alighting. As a result of the survey, a solution is tested to reduce the number of seats in the carriage and create a designated special waiting area for cyclists. This test is conducted experimentally in a laboratory, using a full-scale model of a metro carriage and its corresponding platform. The experiments show that the designated special waiting area for bicycles reduces boarding time and results in a better distribution of passengers inside the carriage, offering a solution that improves both safety and efficiency. This study could contribute to the development of incentive policies for intermodality, which is a key aspect in achieving sustainability in railway transportation systems. Future research will aim to expand this study by including other carriage configurations and a wider variation of demand levels.

1. Introduction

The carrying of bicycles on trains enhances intermodality [1], which is an important concept in sustainability. However, in developing cities such as Valparaíso, most trips are completed without the use of multiple modes (e.g., passengers prefer door-to-door trips using a single mode of transportation). This could be due to a lack of accessibility, which is needed for achieving a proper intermodality, from the beginning of the trip to its end. This requires clear policies to incentivize the carrying of bicycles at metro stations.

To evaluate intermodality at metro stations, Ref. [2] requires an analysis and classification of circulation spaces, both inside and outside the stations. It is important to consider the infrastructure for bike lanes, signage and lighting, services for cyclists, and safety. In addition, other studies [3] show the use of geographic information systems (GIS) for mapping bike–train intermodality data, which is crucial for analysing the knowledge gap and the lack of infrastructure.

The use of bike parking is also a measure that supports intermodality between bicycles and trains [4], in which benefits should be incorporated from a social perspective, showing improvements in emissions and congestion reduction. This requires incentive policies to increase bike parking capacity and prevent cyclists from leaving their bikes outside these facilities, which can negatively affect the comfort and safety of passengers using these spaces. Additionally, by evaluating bike–train intermodality, user profiles and their modal share can be better understood [5]. For example, cyclists prefer larger stations located in city centres over smaller ones in suburban areas.

Incentive policies for bike–train intermodality are promoted mainly in developed cities [6]. The use of adequate spaces within the station can increase intermodality capacity. However, most incentive policies have focused on the use of public bike-sharing systems or fixed parking outside the stations.

Recent studies [7,8] propose micromobility as a way to encourage the reduction of emissions and congestion in cities. This can be achieved through greater modal integration between bicycles and trains. In other words, integration is more important than a bike parking area to achieve intermodal integration.

The promotion of multimodal transport, which involves combining different modes of transportation, e.g., bicycles and the metro system, is one of the proposed solutions to increase the demand during different times of day (peak or off-peak hours). The inclusion of bicycles on the train carriage encourages multimodal transport by allowing passengers to combine the use of the train and the bicycle, which can increase the number of passengers using the metro station and make trips more efficient. However, in cities such as Valparaíso, the issue to be addressed is the limited accessibility to the metro system for people who use bicycles as a regular means of transportation, as they are only allowed to be transported on weekends and holidays. Therefore, the goal is to expand their use, but the impact of this change is unknown. Some of the associated problems and concerns regarding the transportation of bicycles and their integration with the metro system include the following (see Figure 1):

• Limited space: The train cars may have limited space to accommodate bicycles along with passengers, potentially causing more overcrowding and congestion.
• Peak hours: As is known, congestion is quite high during peak hours, and the transportation of bicycles could further hinder passenger comfort and mobility.
• Security: Preventing theft or damage to bicycles can be a significant challenge, especially if the space is not designed for this purpose.
• Interference: Bicycles may interfere with the movement of passengers, making it difficult for them to enter or exit the train.
• Inadequate infrastructure: The lack of bike parking facilities at stations or a designated space on the trains could complicate effective implementation.
• Changes in train design: Existing metro systems may not have been originally designed to accommodate bicycles, which makes adaptation more challenging.

The paper is comprised of seven sections. Section 2 presents the case study. Section 3 refers to the literature review. Section 4 describes the methodology used, based on surveys and laboratory experiments. Section 5 reveals the results of the study, followed by the discussion and conclusions in Section 6 and Section 7.

2. Case Study

The city of Vaparaíso is within the metropolitan area of Valparaíso (Gran Valparaíso), which is composed of five “comunas” (municipalities), Valparaíso, Viña del Mar, Quilpué, Villa Alemana, and Concón, with a population of approximately 1 million, according to the INE (2018) [9]. Regarding the urban mobility of Gran Valparaíso, about 1% of the population use bicycles as a modal transport choice in Gran Valparaíso, according to the Origin and Destination Survey of 2014 (Subsecretaría de Transporte, 2014) [10]. On the other hand, 27% employ walking, 39% used public transportation, and 29% rely on cars. The origin and destination survey demonstrates that in all municipalities, most of the trips are internal. Given this information, it is relevant to highlight that the city of Valparaíso presents higher rates of internal trips in comparison with the other municipalities, including higher rates related to trips for work purposes. For the highly concentrated economic activities in certain areas of each “comuna”, as presented by Caro and Aránguiz (2012) [11], this urban environment still favours the use of private and public transportation because of the “tunnel effect” generated by these systems (Graham and Marvin, 2001) [12]. The “tunnel effect” is related, for example, to highways and public transportation systems intended to reach certain areas that benefit from higher accessibility, i.e., places where there is higher concentration and more diverse offering of transport services. However, intermediate areas along the way are usually not valued or not appealing for local economic development due to the lack of “stopping” infrastructure (e.g., bus stops or train/metro stations), which may cause an unbalanced condition for spatial economic development, in this case, for Gran Valparaíso and its municipalities.

In addition to this information, Valparaíso presents the lowest rates for bicycle trips in comparison with its neighbouring municipalities, which possibly may be related to the topography and slope conditions of the city. Regarding the slope conditions, it has been identified that slopes greater than five degrees are often considered uncomfortable or difficult for cyclists (Erlandsson and Hägglöf, 2016; Midgley, 2009) [13,14]. With respect to e-bikes, this tolerance may increase to 10 degrees (Petron, 2010) [15]. Therefore, the selection of Valparaíso as a case study is based on the fact that it presents the lowest rates of bicycle use because of its potential to break the slope barriers. In addition to this, it is important to look at the bigger picture within the national context. In this regard, Chile has adopted the Sustainable Development Goals (SDGs) presented by the United Nations (United Nations, 2017) [16] as a reference. Of these 17 goals, one concerns the creation of “Sustainable Cities and Communities” (UNDP, 2018) [17], in which a relevant pillar is related to the development of sustainable mobility. One must consider that major challenges today are related to building cities that are inclusive, safe, resilient, and sustainable (UNDP, 2018; Henrıquez, Azocar, and Romero, 2006) [18]. In this context, the promotion of non-motorized mobility is a growing interest in Chile for the reduced cost of implementation and its benefits regarding sustainability dimensions. In this direction, the promotion of non-motorized modes such as cycling as a main mobility option can be beneficial in the urban context.

Considering the previous context, the use of other means of transportation is required to promote the bicycle as an active mode of transport for various activities such as education, work, and leisure. In this regard, the train presents a unique opportunity to enhance intermodality between this public transport service and the bicycle [19,20,21]. In the case of Valparaiso, the whole train network consists of 20 stations over the five “comunas” previously defined (42 km long). The coastal overground stations include (shown in Figure 2 from 1 to 6) Puerto, Bellavista, Francia, Baron, and Portales. The underground stations (shown in Figure 2 from 7 to 10) comprise Miramar, Viña del Mar, Hospital, and Chorrillos. The interior overground stations are (shown in Figure 2 from 11 to 20) El Salto, Quilpue, El Sol, El Belloto, Las Americas, La Concepcion, Villa Alemana, Sargento Aldea, Peñablanca, and Limache.

3. Literature Review

According to Martens [22], bicycles are essential to achieve intermodality with other modes such as trains. Taking the UK, the Netherlands, and Germany as case studies, the author focused on multimodal choices to increase the ridership between bicycles and public transport, in which most of users travel between 2 and 5 km to a public transport stop due to work activities. In the same vein, Kager et al. [23] considered the bicycle as a feeder mode of transport to access public transport, in which the speed of the train, the accessibility, and the flexibility of combining modes are main factors that should be considered. In the case of Asian cities, Ji et al. [24] contributed to determine the main factors that affect the use of the bicycle as a feeder mode of transportation, including personal demographics, trip characteristics, and station environment. Therefore, to achieve intermodality, different infrastructures, programs, and policies are needed [25].

In the case of Chile, different policies have been developed in the recent years. For instance, at a national level, the country has taken a step forward by approving an initial modification of the current traffic law that regulates the use of different types of vehicles, also changing its name to “Ley de Convivencia Vial” [26]. Furthermore, these initial changes seek to determine places where cyclists may or may not circulate, a minimum distance between cyclists and motorized vehicles, and other parameters. However, this law still lacks more concrete parameters for cyclists to better integrate with public transport, e.g., parameters regarding carrying bicycles inside the train carriage. More importantly than the specifics of the law, the enactment of the law itself shows the interest of the country in building more equitable cities by focusing on the spatial usage of all modes, with particular attention to non-motorized modes, such as biking. Although this law may not oblige the implementation of infrastructure for cyclists, it may be an influential factor if there is an increase in intermodality in cities of the country in coming years. Bicycles are also sustainable modes, as they are non-polluting and non-resource intensive, with a reduced cost of maintenance, and their usage can be beneficial for health [27], in addition to providing benefits regarding the sustainable dimensions of transport and mobility [28,29].

For this reason, the current study proposes to explore the potentiality of carrying a bike inside the train carriage at metro stations for daily mobility. This study can overcome one of the geographical barriers outlined in mobility perception-related studies [30,31], specifically the steep hills of Valparaíso. In this direction, it is relevant to highlight that in Chile, bikes are classified as non-motorized vehicles, with no need for a specific license [26]. Therefore, it can be a potential solution for promoting sustainable mobility in Valparaíso, if citizens are willing and able to shift their mobility patterns. It is interesting to observe that other studies on the barriers of bicycle use have identified that adequate infrastructure is a key factor for promoting this mode as a daily mobility choice [32,33], highlighting, for example, case studies in Brazilian cities, which included similar slope conditions to those of Valparaíso. In this direction, this raises the following academic question regarding intermodality and sustainable mobility: Does the lack of infrastructure dedicated to bicycles limit citizens in carrying their bikes onto the train carriages at metro stations? In the case of Valparaíso, which is the municipality of Gran Valparaíso, with steeper slopes and less usage of bicycles, it seems that the challenge is not those 0.4% that already confront the hilly conditions and other problems of the city, but to understand the reasons why the other 99.6% of trips are not performed using the two-wheel mobility option, specifically bikes, which seems more adequate for use in this city.

Beyond its complex topographic conditions, Valparaíso presents a complex socio-spatial setting, expressed by the inequality of income and residential segregation [34,35]. This issue may significantly affect individuals’ behaviour towards mobility [36]. For this reason, it is essential to employ qualitative methods and an exploratory approach, aiming to collect information related to perceptions and experiences [37] within the particular context of the city of Valparaíso with a specific focus on bikes. Therefore, this study consists of qualitative and quantitative approaches to assess the potential carrying of bikes inside a metro carriage in Valparaíso and its contribution to sustainable mobility through experimental research.

4. Methodology

The methodology to be used follows a four-stage process, employing an observation and experimentation approach. In the first stage, the factors that affect the capacity of a train carriage for bicycle carrying are identified. To do this, an on-site observation is carried out by visiting metro stations. As a case study, a representative sample of metro stations from Valparaíso is considered, taking into account their specific characteristics and needs (e.g., type of station, passenger flow, etc.). The observation is carried out at different times of the day to check for any differences between peak and off-peak hours, considering different levels of congestion. The number of cyclists and cycling facilities, such as bicycle parking, at the stations are recorded (see an example of bicycle parking at the Francia Station in Figure 3).

In the second stage, the analysis variables are defined based on the field observation. These variables are divided into three categories for metro stations, following the methods used in the study by Ref. [38]:

• Physical variables: These refer to the dimensions of circulation elements within a metro station, such as width, length, etc. (e.g., the length and width of the train carriage).
• Spatial variables: These are identified as elements that influence passenger behaviour, such as the use of facilities for cyclists (e.g., bicycle parking, handrails for stairs, platform markings, etc., as shown in Figure 3).
• Operational variables: These are recorded as key variables for conducting an operational diagnosis of a metro station, such as passenger density, train frequency, and platform evacuation time.

In the third stage, experimentation is conducted in the laboratory. For this, the Mobility and Transport Laboratory at Pontificia Universidad Católica de Valparaíso (PUCV) was used. It is equipped with a model of a train carriage (2.5 m wide and 7 m long) and its corresponding platform (3 m wide and 5 m long). The model of the carriage is representative of a train carriage from EFE Valparaíso (see Figure 4).

In Stage 3, data collection is carried out, meaning that data must be gathered for factors such as the average number of passengers per carriage, representative times (e.g., peak or off-peak hours), trip duration, and representation of the busiest stations. Additionally, in this stage, a pilot survey is conducted to determine how passengers interact with bicycles on a train and how this affects the train’s capacity. It is important that the areas to be studied are defined in this stage. The following aspects are proposed for definition:

• Stations: Design specific areas for bicycle parking and securing at metro stations.
• Carriages: Evaluate how to safely and efficiently accommodate bicycles in the carriages, including the design of folding seats or storage areas.
• Number of bicycles: Establish limits on how many bicycles can be carried in a carriage or designated area.
• Timings: Define specific times during which bicycles are allowed on the trains.
• Size and types of cyclists: Identify safe and convenient routes for cyclists to travel from metro stations to their final destinations.
• Signage: Install clear signage in stations and carriages to indicate where bicycles are allowed.
• User feedback: Collect feedback from passengers regarding the implementation of the plans and make adjustments as needed.
• Users and safety regulations: Educate users on how to transport their bicycles properly and respectfully and inform them about the rules and regulations to follow to prevent uncomfortable or dangerous situations for passengers.

Stage 4 is the result of what is carried out in Stage 3. This is because, based on the experimental modelling, the space and capacity calculations are completed to determine how much space an average bicycle will take up in a train carriage and how to distribute passengers and bicycles (see Figure 5). Based on the evaluation of overcrowding (how bicycles affect overcrowding levels under different conditions), a SWOT (strengths, weaknesses, opportunities, and threats) analysis of implementing the proposed scenarios is carried out. This evaluation should include visual counting (observing the number of passengers in the carriage to get an idea of when and where overcrowding occurs) and comparing the number of passengers with the maximum capacity of carriages and stations to determine the level of occupancy. Recommendations may be supported by experts at the metro system in Valparaíso through consultations and technical meetings to obtain their input and possible solutions.

5. Results

5.1. Data Collection from Metro Stations

The data collection consisted of the identification of different variables which were obtained through observation in the metro stations. From the variables obtained at metro stations, the layout of the train carriage, representative times (e.g., peak and off-peak hours), and the representation of the busiest station were registered. Figure 6 shows the layout of the train carriage (half of the total length), in which the maximum capacity is equal to 518 passengers at a density of 6 passengers per square meter. The train has 92 fixed seats, plus 12 tip-up seats. Most of the seats are located perpendicular to the movement of the train; however, the tip-up seats are located parallel to the movement of the train. Next to the tip-up seats, passengers have more space available to use when carrying a bike compared to that in the section of the train closer to the fixed seats, in which the corridor is about 90 cm wide. Additionally,

Table 1. Accessibility conditions of the train carriage when carrying bicycles in Valparaiso Metro.

Element	Description	Accessibility Achieved (Yes or No)
Seats	Preferential seating is distributed across all carriages and proper positioning of the seat (opposite to or in the same direction as the train’s movement); seat placement adequate to ensure it does not obstruct access to bicycles.	Yes
Reserved space	Sufficient space of 2 × 1 m for a bike in at least one carriage.	No
Signage	Door signage indicating preferential use of bikes inside the train carriage.	No
Sound and lighting	Audible and visual indicators, perceptible both inside and outside, with contrasting colours.	Yes
Floor	Train floor non-slip and with colour contrast compared to the platform floor.	No
Vertical handrail	Placement of vertical handrails to ensure they do not obstruct access to the train.	Yes
Door and aisle	The width of the doors must allow for unobstructed access to the train. The distance between the door and the seats (setback) is also important. Additionally, the minimum width of 80 cm must be maintained for the train aisle (to allow movement towards the seats).	Yes
Steps	The number of steps between the train and the platform should ideally be zero (at the same level).	Yes

shows more details of the layout of the train carriage, considering the lack of signage and reserved space (i.e., accessibility conditions) when carrying a bicycle.

The representative time was obtained considering the behaviour of passengers during the morning peak hour (MPH, from 7:00 a.m. to 9:00 a.m.) and the afternoon peak hour (APH, from 5:00 p.m. to 7:30 p.m.). The most congested station is Francia, in which more than five thousand passengers alight during the MPH (see Figure 7) in the train service from Limache Station (11,974 passengers board) to Puerto Station (4453 passengers alight).

5.2. Survey

In the case of the survey, in total, 190 participants were registered.

Table 2. Age distribution of participants in the survey.

Age	Number of Participants	Percentage
18–24	57	30.0%
25–35	42	22.1%
36–50	49	25.8%
51–60	35	18.4%
61 or older	7	3.7%

shows the age distribution of the surveyed users. Age can significantly influence the passengers’ perceptions of comfort and their needs. For example, younger people (18 to 35 years old) tend to be more willing to use bicycles and may be more tolerant of travel conditions with less space. On the other hand, older individuals (51 years or older) may prioritize comfort and personal space, being less tolerant of overcrowding or the presence of bicycles.

Of the total participants, most of them lived in Viña del Mar (40%), with 16.3% in Valparaíso, 12.1% in Villa Alemana, and 20.5% in other “comunas”. Knowing the city of residence of the surveyed participants helps identify where the highest demand originates for users who wish to transport bicycles on the metro. In the context of Greater Valparaíso, this could indicate which areas or specific stations experience a higher demand for bicycle space, such as Viña del Mar, helping to focus infrastructure improvements or define specific policies for certain metro lines to optimize the flow of passengers and cyclists.

In addition, a high percentage of respondents (73.5%) use the metro as their mode of transportation, which reaffirms the importance of the Greater Valparaíso metro system for interurban mobility.

When asking participants how often they used the metro as their mode of transportation (per week), an important number of respondents mentioned a high frequency of metro use. The participants needed to choose between the following answers: (a) every day (5 days a week), (b) several times (3 days a week), (c) only occasionally (1 day a week), or (d) none (not using the metro system during the week). This frequency is a key indicator of how familiar passengers are with the daily conditions of the carriages and the interaction between bicycles and passengers. Those who use the metro daily or several times a week are likely to have a clear perspective on the impact that the presence of bicycles has on their travel experience. In this case, we see a high percentage of frequent metro use (63%), considering those who report using it “every day”, “several times”, and “only occasionally”.

Another relevant piece of data to understand the potential impact of the use of bicycle transport services on the metro is the high percentage of respondents who report owning a bicycle (62.8%), highlighting the popularity of this mode of transport.

When asked if they have tried using a bicycle inside the metro train (yes or no answer), it is observed that at least one-third of the respondents have used an intermodal transport method (bicycle + metro) to get around. However, this remains a low percentage, considering the number of respondents who reported owning a bicycle. This suggests the need to implement permanent solutions to further encourage bicycle carrying and the coexistence of cyclists and passengers inside the train carriage. Moreover, the frequency with which users have taken their bicycles on the metro in the past month reflects how regular this practice is. Frequent use suggests that passengers see the metro as a viable and necessary option for their daily or weekly bicycle trips, highlighting the importance of providing this option in a structured manner. If the use is low, it could indicate that only a minority of passengers need to bring bicycles, and that the current infrastructure may be sufficient to meet this limited demand.

User satisfaction with the carriage’s capacity to transport bicycles is crucial. The participants were asked to declare their satisfaction on a scale of 1 (very dissatisfied) to 5 (very satisfied). In this case, more than half of the respondents (51.2%) reported feeling “dissatisfied” or “very dissatisfied” with the current capacity to accommodate both cyclists and other passengers without compromising the comfort of either group. This low level of satisfaction could be a wake-up call to expand the available space for bicycles or design specific areas that do not interfere with the flow of other passengers. However, the high level of agreement expressed by the respondents suggests that passengers are willing to share space with bicycles, which facilitates the implementation of inclusive policies and, in turn, serves as an incentive for intermodal transport methods.

Moreover, participants were asked if they think that carrying a bike inside the train should be allowed (yes or no answer). The results show that there is a strong preference for allowing bicycles daily (83%), suggesting that there would be a stable and consistent demand, meaning that the metro could plan infrastructure to support this practice on a daily basis.

When asked how comfortable they feel traveling in the carriage with the presence of bicycles, the results indicate that the level of comfort passengers experience when traveling in the same carriage as bicycles is a relevant factor. Participants were asked to identify their level of comfort using a scale of preference from 1 (very uncomfortable) to 5 (very comfortable). In this case, significant percentage of respondents (73.6%) reported “indifference”, “comfortable”, or “very comfortable” with the presence of bicycles inside the carriage, suggesting that passengers do not feel great inconveniences when sharing the space with cyclists.

Finally, participants were asked what solutions they would propose to achieve the intermodality of bicycles within the train carriage, e.g., the solutions users consider most appropriate if bicycle transport were allowed every day. These options may include specific carriages for bicycles, restricted hours, or clear regulations regarding the space bicycles can occupy. Most of participants (62.3%) considered reducing the number of seats to achieve a wider space for bicycles inside the train carriage as the best solution. This information is valuable for implementing changes that respect both cyclists and other passengers, promoting a harmonious environment on the metro.

5.3. Experiments

In this section, the results of the experiments are presented. During the experiments, three modelling scenarios were employed. These are detailed below (see Figure 8).

The setup of the experiments consists of half of a train carriage (3.5 m long by 2.5 m wide), where seats, aisles, and an entrance hall are considered. In each area, there are vertical and horizontal handrails to provide safety and comfort for passengers. One double train door is considered (1.3 m wide).

The three scenarios were modelled in the experiments, considering participants who board and alight from the train carriage. In the first instance, participants board an empty train carriage in Scenario A, where there are eight seats and no special bike waiting area. They then alight to wait on the platform. In the second instance, participants board an empty train carriage in Scenario B, where there are four seats and a special bike waiting area for two bicycles. They then alight to wait on the platform. Finally, in the third instance, participants board an empty train carriage in Scenario C, where there are no seats and two special bike waiting areas for three or more bicycles.

In each scenario, three levels of demand were considered. Firstly, a low level of demand is considered, in which the participants board the train carriage and distribute themselves randomly, considering only one bicycle in the boarding/alighting process. Secondly, a medium level of demand is used, where more participants board and distribute themselves randomly, and two bicycles are used in the boarding/alighting process. Thirdly, a high level of demand is registered, in which more participants board and distribute themselves randomly, but three bicycles are considered in the boarding/alighting process. This process is repeated twice for each scenario.

The results are presented in

Table 3. Results from the scenarios modelled in the experiments.

Scenario	Number of Participants Boarding	Number of Participants Inside the Train Carriage	Total Participants	Boarding Time
A—low demand	five passengers + one passenger carrying a bike	0 passengers	five passengers + one passenger carrying a bike	5 s or 0.83 s/passenger
A—medium demand	six passengers + one passenger carrying a bike	five passengers + one passenger carrying a bike	11 passengers + 2 passengers carrying a bike	7 s or 1 s/passenger
A—high demand	four passengers + one passenger carrying a bike	11 passengers + 2 passengers carrying a bike	15 passengers + 3 passengers carrying a bike	7 s or 1 s/passenger
B—low demand	five passengers + one passenger carrying a bike	0 passengers	five passengers + one passenger carrying a bike	5 s or 0.83 s/passenger
B—medium demand	seven passengers + one passenger carrying a bike	five passengers + one passenger carrying a bike	12 passengers + 2 passengers carrying a bike	7 s or 0.875 s/passenger
B—high demand	five passengers + one passenger carrying a bike	12 passengers + 2 passengers carrying a bike	17 passengers + 3 passengers carrying a bike	9 s or 1.5 s/passenger
C—low demand	five passengers + one passenger carrying a bike	0 passengers	five passengers + one passenger carrying a bike	4 s or 0.67 s/passenger
C—medium demand	seven passengers + one passenger carrying a bike	five passengers + one passenger carrying a bike	12 passengers + 2 passengers carrying a bike	6 s or 0.75 s/passenger
C—high demand	five passengers + one passenger carrying a bike	12 passengers + 2 passengers carrying a bike	17 passengers + 3 passengers carrying a bike	7 s or 1.16 s/passenger

. In Scenario A, with a low level of demand (an average of five participants and one person with a bicycle), most people sit in the available seats. The person with the bicycle positions themself at the end of the aisle, while only one person is located in the entrance hall of the train carriage (see Figure 9). The boarding time, calculated as the time from when the first passenger enters the train carriage until the last passenger boards the train carriage, is 5 s, or 0.83 s per passenger. If seven more passengers board the train carriage, and one of them is using a bicycle (i.e., medium level of demand), more congestion occurs. All the seats are occupied, and the second person with a bicycle positions themself in the entrance hall along with two other people. These passengers take 7 s, which is equivalent to 1.0 s per passenger. If five more people board the train carriage (i.e., high level of demand), one of whom is carrying a bicycle, there are now three bicycles inside the carriage, resulting in a high level of congestion at the aisle and the entrance hall. It takes a total of 7 s for them to board the subway car, which is equivalent to 1.4 s per passenger.

In the case of Scenario B, the same sequence of demand levels is applied to each modelling scenario. Figure 10 shows that the special bike waiting area provides more available space to accommodate passengers entering the train carriage. In the case of low demand (five passengers and one person with a bicycle), the boarding time is 5 s, equivalent to 0.83 s per passenger. That is, there is no variation compared to Scenario A. However, the distribution of passengers is more suitable, as the special bike waiting area is used, along with all available seats.

For medium demand (i.e., eight more passengers boarding, including one with a bicycle), congestion increases; however, the special bike waiting area allows for the accommodation of both bicycles without problems, reducing bike–passenger interactions and enabling passengers to occupy the entrance hall more fully. In this case, the boarding time is 7 s, equivalent to 0.875 s per passenger. This value is 12.5% lower compared to that in Scenario A (which lacks a special waiting area for cyclists).

Even with a high demand level (i.e., six more passengers boarding, including one with a bicycle), the boarding time is not significantly higher, reaching 9 s, or 1.5 s per passenger. This value is 7% higher compared to that in Scenario A (where there is no special bike waiting area). This increase is due to the reduction of seats and the greater congestion in the entrance hall in high-demand situations, making the boarding process slightly slower.

Finally, in Scenario C, there is more available space to accommodate bicycles inside the subway car, as there are no seats, and bicycles can be placed in two special waiting areas. For a low demand level (five passengers plus one person with a bicycle), the boarding time is 4 s, or 0.67 s per passenger, which represents a 20% decrease compared to that in Scenarios A and B (where the time is 0.83 s per passenger).

Even for a medium demand level (eight additional passengers, one of whom is carrying a bicycle), the boarding time is 6 s, or 0.75 s per passenger, which is 14% lower than that in Scenario B (which reaches 0.875 s per passenger).

Furthermore, for a high demand level (six more passengers boarding, one of whom is carrying a bicycle), the boarding time is 7 s, which gives a value of 1.16 s per passenger. This is 22.2% lower compared to that in Scenario B (which reaches 1.5 s per passenger) and 17% lower compared to that in Scenario A (which reaches 1.4 s per passenger).

6. Discussion

To identify the strengths, weaknesses, opportunities, and threats, a SWOT analysis is performed for the case study. SWOT is a strategic tool that allows for a comprehensive evaluation of both internal and external factors that may influence the success of a project [39]. In this case, the aim is to investigate how the inclusion of bicycle spaces in train carriages can affect the train’s capacity and passenger overcrowding, as well as the efficiency of transport. This analysis serves the following functions:

• Identifies strengths. It helps identify the capabilities and resources already inherent in the project already, such as alignment with sustainable trends and the promotion of intermodality. It also facilitates leveraging the positive aspects of the project to enhance its success.
• Detects weaknesses. It helps identify internal areas that need improvement, such as limited carriage capacity and adaptation costs, and allows for planning how to address these weaknesses to minimize their negative impacts.
• Explores opportunities. It allows for the identification of external opportunities such as the growing demand for sustainable mobility and the potential for funding and grants. It helps prepare strategies to capitalize on these opportunities, improving the project’s scope and feasibility.
• Anticipates threats. It detects external factors that could hinder the project, such as passenger resistance and regulatory issues, and facilitates the creation of action plans to face and mitigate these threats.

The inclusion of bicycle spaces in trains responds to a growing demand from users who combine bicycle use with rail transport, thus promoting sustainable mobility. However, this initiative must be carefully evaluated to ensure that it does not compromise passenger comfort or the operational efficiency of the trains (see

Table 4. SWOT analysis when using bikes inside trains in the metro system in Valparaíso.

Strengths Promotes bicycle use, reducing the carbon footprint and encouraging healthy lifestyles. Facilitates the combination of different modes of transportation, improving accessibility and convenience for users. Can attract more passengers who currently use cars, increasing the economic viability of the rail system. Can align with governmental and corporate sustainability policies, strengthening its international support.

Opportunities Promotes a healthier lifestyle. Encourages the creation of tourist routes and business opportunities. Leverages the trend toward more environmentally friendly and efficient modes of transportation. Allows for potential access to government or international organization funds that promote sustainable mobility projects. Encourages the development of complementary infrastructure.

Weaknesses Implementing bicycles in the metro could lead to overcrowding and congestion issues, especially during peak hours. The lack of adequate facilities in some stations may limit efficiency. Modifying existing carriages or acquiring new ones with specific spaces for bicycles could entail significant costs.

Threats Some people may resist the cultural shift of combining bicycles and trains, which could affect the adoption of this practice. The combination of bicycles and trains may pose safety challenges, especially if proper measures are not implemented. The lack of effective implementation may lead passengers to opt for more comfortable and direct means of transport. If passenger space and comfort are compromised, it could negatively impact customer satisfaction and the service’s reputation.

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Integrating bicycles into train carriages presents significant opportunities to improve mobility and encourage an active and sustainable lifestyle. However, it is essential to address weaknesses, such as space limitations and the lack of infrastructure, to ensure effective implementation. Overcoming threats, such as cultural resistance and safety risks, is also crucial. Overall, the study provides a solid foundation for improving the user experience and addressing passenger overcrowding in a more sustainable way. If trains do not accommodate bicycle riders by providing proper facilities, many cyclists will be forced to seek alternative modes of transportation, such as motorcycles or cars. This shift in transportation choices can have significant negative consequences for sustainable mobility. As more people opt for using personal vehicles, the demand for road space increases, leading to traffic congestion, longer travel times, and higher levels of air pollution. Moreover, this shift undermines efforts to reduce carbon emissions, as motorcycles and cars contribute more significantly to greenhouse gas emissions than do bicycles or public transport. Additionally, the increased reliance on motorized vehicles further strains urban infrastructure. Ultimately, neglecting the needs of bicycle riders in train systems contributes to the broader challenge of creating a more sustainable and eco-friendly transportation network, making it harder to achieve goals related to reducing carbon footprints, promoting public transport, and encouraging active mobility.

From the survey, key insights about metro passengers’ experiences with transporting bicycles are highlighted. The demographic information highlights the locations in which the demand for bicycle transport on the metro is highest, particularly identifying Viña del Mar, which could guide infrastructure improvements and policy decisions aimed at optimizing the flow of passengers and cyclists. In addition, a significant percentage of respondents (73.5%) use the metro regularly, emphasizing its importance for interurban mobility in the Greater Valparaíso area. About 63% of participants reported frequent metro use, which suggests a strong familiarity with the daily conditions of the carriages, including how bicycles affect the travel experience. Moreover, 62.8% of respondents own a bicycle, pointing to the potential demand for bike-friendly metro services.

However, despite owning bicycles, the survey highlighted that only about one-third of respondents have used the metro for intermodal travel (bike + metro), indicating that the current infrastructure may not fully support this option. This calls for solutions to better accommodate cyclists and encourage more regular carrying of bikes on the metro. For instance, user satisfaction regarding the metro’s capacity to transport bicycles is low, with over half (51.2%) of respondents expressing dissatisfaction with the current setup. Many passengers are open to sharing space with bicycles, but there is a clear need for designated areas to ensure comfort for both cyclists and other passengers. Furthermore, 83% of respondents support allowing bicycles daily, indicating a consistent demand for such services. When asked about their comfort with bicycles in the carriage, 73.6% of respondents felt indifferent or comfortable with the presence of bikes, suggesting minimal discomfort. Regarding potential solutions for better integrating bicycles on the metro, 62.3% of participants favoured reducing the number of seats to create more space for bikes, indicating a preference for practical adjustments to accommodate both groups. These findings suggest implementing special waiting area for bikes, with a capacity of three bicycles, which could be complemented with policies that balance the needs of cyclists and regular passengers to promote intermodal transport.

On the other hand, the results of the experimental study show how different levels of demand (low, medium, high) affect boarding times and passenger distribution in three train carriage scenarios (A, B, and C). In Scenario A (no special bike areas), for a low demand (five passengers + one bicycle), the boarding time is 5 s (0.83 s per passenger), with most passengers occupying available seats and one bicycle placed at the end of the aisle. The medium demand (seven more passengers + one bicycle), in which all seats are occupied, and a second bicycle is placed in the entrance hall, with two additional passengers, presented a boarding time which increased to 7 s (1.0 s per passenger). The high demand (five more passengers + one bicycle) included three bicycles and caused significant congestion in the aisle and entrance hall, increasing the boarding time to 7 s (1.4 s per passenger).

In Scenario B (with special bike waiting areas), a low demand (five passengers + one bicycle) reached a boarding time which remains the same as that for Scenario A (5 s, 0.83 s per passenger), but the special bike waiting area provides better passenger distribution. The medium demand (eight more passengers + one bicycle) increased the congestion, but the bike waiting area accommodated both bicycles, reducing interactions between bikes and passengers. The boarding time was 7 s (0.875 s per passenger), which was 12.5% lower than that for Scenario A. In the high demand (six more passengers + one bicycle) the boarding time increased to 9 s (1.5 s per passenger), 7% higher than for Scenario A, due to fewer seats and more congestion.

Finally in Scenario C (no seats, two special bike waiting areas), the low demand (five passengers + one bicycle) reached a boarding time which was reduced to 4 s (0.67 s per passenger), a 20% improvement compared to that in Scenarios A and B. The medium demand (eight more passengers + one bicycle) obtained a boarding time which was 6 s (0.75 s per passenger), 14% lower than that in Scenario B. The high demand (six more passengers + one bicycle) registered a boarding time which was 7 s (1.16 s per passenger), 22.2% lower than that in Scenario B and 17% lower than that in Scenario A.

In summary, Scenario C, with more space for bicycles, offers the shortest boarding times, especially in high-demand situations, while Scenario B, with dedicated bike areas, performs better than Scenario A in terms of boarding efficiency.

7. Conclusions

The study of the train carriage capacity for bicycle carrying and its effect on passenger overcrowding is a relevant topic in public transport planning and the promotion of sustainable mobility. However, like any research, it must be conducted with a careful focus on its scope and limitations.

The study of train carriage capacity for bicycle transport can be further expanded to assess the future capacity of trains to accommodate bicycles. This would involve considering additional factors such as the size of the carriages, the interior design, and the space layout to ensure that there is sufficient room for both passengers and bicycles. Additionally, the integration of bicycle transport within train carriages can be evaluated in further experiments to better understand how it impacts users’ multimodal mobility. This would include examining how the option to bring bicycles on board affects passengers’ travel decisions and how bicycles and trains interconnect within the broader transport network.

Based on the findings from such studies, recommendations can be developed to improve space management inside train carriages and optimize the integration of bicycle transport. The goal would be to reduce overcrowding and enhance the overall user experience for both cyclists and other passengers. However, it is important to note that transport conditions can vary significantly between different metro systems and routes, which could limit the ability to generalize the study’s findings to other locations or contexts. Additionally, other factors—such as population density, service frequency, and space management policies—may also influence passenger overcrowding, making it challenging to isolate the specific impact of bicycle transport on these issues.

In addition, as a next step in this investigation, a comprehensive study of local economic development will be conducted to explore the intricate relationship between the lack of infrastructure and the resulting imbalances in spatial economic development in Valparaiso. This analysis will aim to identify how insufficient or poorly distributed infrastructure contributes to disparities in economic opportunities across different areas of the city. Furthermore, the study will examine the broader socio-economic impacts of these imbalances, considering factors such as employment, access to services, and regional growth. By focusing on these aspects, the research will provide valuable insights into how targeted infrastructure improvements could help foster more equitable and sustainable economic development throughout Valparaiso, addressing both the challenges and potential solutions for overcoming spatial inequalities.

Cultural and social factors also play a role in shaping passengers’ attitudes and behaviours toward both bicycle transport and public transportation. These factors can be difficult to quantify in a study, but they are important for understanding how different groups of passengers might respond to changes in metro policy. Seasonal and climatic conditions may further complicate the analysis, as weather patterns and varying seasons could influence the carrying of bicycles, in combination with metro services. As a result, long-term studies may be necessary to capture more accurate data on this subject by testing different configurations inside a carriage in existing stations. Lastly, implementing improvements to train car capacity for bicycles may require significant investments in infrastructure and transport policies, which could be constrained by available financial and political resources.