1 Introduction

The concept of “sustainable development” is regulated in Article 3 of the Polish Environmental Law which provides the following definition: sustainable development is social and economic development which involves the integration of political, economic and social activities while maintaining the natural balance and sustainability of basic natural processes, in order to guarantee that the fundamental needs of the community or citizens belonging to the present and future generations are satisfied (Dz.U. – Journal of Laws – 2001, No. 62, item 627 of 20 June 2001). According to OECD (2011), sustainable development means supporting economic growth and development while ensuring that natural assets continue to provide the environmental resources and services which contribute to our prosperity. The issue of sustainable development is examined by numerous researchers: Parris and Kates (2003), Egelston (2012), Kahle and Gurel-Atay (2014), Sachs (2015), Mensah (2019), Dehghanmongabadi and Hoşkara (2020). From the analysis of the mentioned references, sustainable development is a complex concept, encompassing the entire area of human activity and aiming at improving the quality of life of both current and future generations (ONZ, 2015).

Moreover, the issue of sustainable development includes the environmental impact of transport. The aim of sustainable development in the transport services market is to provide the society with a far-reaching vision of development which would meet its current needs in the long term. The issue of reducing the adverse impact of transport on the environment has been reflected in key European transport documents. The objectives set out in subsequent Green and White Papers on transport, including the European Commission's White Paper on Transport, are aimed at alleviating the adverse environmental impact of transport by 2050 (European Commission, 2010). This issue is also discussed in the works of numerous authors (Makarova et al. 2017), who analyse the adverse effects of transport development and recognise the need for change both in terms of passengers and cargo (Nijkamp 1994; Gudmundsson and Höjer 1996; Raitasuo et al. 2019). The rationale behind this approach is the rapid development of transport and traffic with its negative consequences: traffic congestion, air and noise pollution, problems with road safety, which are caused to a much greater extent by road transport than by rail transport (Deakin 2001; Wang et al. 2018; Akinyemi and Zuidgeest 2000).

To achieve these objectives, both the state and local governments take measures to reduce road traffic, including mainly those caused by private transport, and create conditions for the development of rail passenger transport. They are not yet fully developed and require continuous improvement (Antonowicz 2017).

One of the factors encouraging the use of public transport – services of rail and bus operators – are the rising costs associated with using a car in the city. The paper focuses on the analysis of young passengers' preferences which are the basis for the choices they make regarding rail and bus public transport. Passenger transport in Poland is presented in Table 1.

Table 1 Passenger transport by mode (all types of passenger transport)
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As the data presented suggest, the passenger transport market in Poland is highly dynamic and is undergoing constant transformations resulting mainly from changes in the transport environment. A reduction in the number of public road transport passengers is primarily attributable to the development of private transport. According to Eurostat data, the number of cars per 1000 inhabitants increased in Poland from 261 to 610 between 2000 and 2018. This is the highest increase in the motorisation coefficient among 27 European Union countries (Eurostat, CSO, 2019). In contrast, the period from 2019 to 2021 was marked by the COVID-19 pandemic, during which individuals largely refrained from traveling, visiting friends, and attending in-person work or educational settings, instead opting for remote options. These restrictions precipitated a significant reduction in transportation.

Today’s market of transport services is, therefore, the buyer’s market in which operators representing different modes of transport are competing over the customer. A potential customer has an actual choice between a passenger car, bus or train.

The article is structured as follows: Introduction on the concept of sustainable development, Theoretical Background including a review of literature related to passenger behaviour and preferences in rail and road transport, Research Methodology which includes a description of the method and research tool as well as structure of the research sample, Sect. 4 Research Results which presents the results of a survey among young travellers in Poland. Section 5 provides Discussion and Conclusion.

2 Theoretical background

The studies and analyses carried out indicate that passenger transport operators compete primarily on such instruments as the product (time, comfort and safety, physical accessibility and number of connections) and price (Rosa 2020, p. 108, Kos et al. 2020, p. 114). Rolling stock is being successively renovated, both by road transport and rail operators (with participation of the state and local governments), customer service is improving as well. Infrastructure development “reduces” the distance between regions and has a positive impact on the unity of the national market (Koźlak 2010). Drivers have more and more expressways and motorways at their disposal, which has improved the safety of car travel and significantly shortened travelling time between Poland’s major cities. The pursuit of sustainability objectives fosters environmentally friendly investments in rail transport. The potential of railways in Poland and other European countries may be compared on the basis of the average number of passenger trains passing daily on a statistical kilometre of railroad tracks. In Poland, an average of 20 passenger trains passes each day on one kilometre of railroad tracks, i.e. about 7 times less than in the Netherlands. The European average in this category is 45 trains per 1 km of railway line (Wykorzystanie i potencjał kolejowych przewozów pasażerskich w Polsce 2017, p.11).

The experience and solutions introduced in other countries may be useful in achieving the defined objectives. Switzerland has the highest rate of railway use in Europe, with nearly 70 journeys per capita per year. Rail services in this country are characterised by (Wykorzystanie i potencjał kolejowych przewozów pasażerskich w Polsce 2017, p. 11):

  • High availability of rail services (large number of trains per day and cyclical train timetable);

  • Reliability;

  • Travel comfort (comfortable and well-muted cars available even in regional transportation);

  • Well-organised connections with other modes of transport, as well as a wide range of services offered under a single ticket for all modes of transport.

An analysis of the approaches to passenger transport presented in the literature reveals that if such services are relatively reliable, customers will be satisfied with the service provided (Paprocki 1996; Wyszomirski 1994, 1998; Tomanek 2002; Engelhardt 2018). The said authors highlight the traditional elements of transport services which are the most important in gaining a competitive advantage on the market. Evolution of the transport market, increasingly strong competition and changes in customer expectations have led to the emergence of new areas and instruments of competition alongside the traditional ones. An analysis of the available results in the literature indicates that the provision of reliable services is insufficient while maintaining a strong competitive position in a changing environment. The importance of standard services is diminishing. The role of knowledge, cooperation skills, entrepreneurship and innovation is growing. The importance of innovation in the field of transport services, technology as well as customer relations is recognised (Kos et al. 2018; Drewnowski 2019).

Passenger preferences in rail transport are also studied extensively worldwide in order to produce specific solutions, e.g. Muñoz and de Grange (2010) for Santiago, or referring to the quality of services (Nocera 2010; Eboli and Mazzulla 2011). The models suggested in the works of Eboli and Mazzulla (2015) and Eboli et al. (2018) suggest the possibility of quantifying transport service quality. Results of the above studies demonstrate that respondents (passengers) consider the following as the most important elements of services: frequency, timeliness, comfort, cleanliness and information. Similar results are presented in the studies by de Oña et al. (2014). Today's authors recognise changes in behaviours of transport passengers and new trends in their preferences. It is important to constantly monitor these changes and adapt the system accordingly, as is confirmed by results of the studies of de Oña et al. (2018). Preferences of rail transport passengers stem from the necessity to satisfy transport needs, which reflect their expectations and personality. Customers are increasingly demanding in respect of, for example, the quality of services offered (Kos et al. 2020), safety, provision of current information (Guszczak 2014), customer service (Antonowicz 2019), often even comprehensive logistics service on a national and international scale (Krawiec and Ćwiek 2019; Massel 2019; Mężyk 2019; Szałucki 2019). Studies of the above authors show that customers assess which of the services, regardless of their motives, will provide them with the highest value and then opt for that service. Whether the service meets their expectations or not affects customer satisfaction and the likelihood that they will purchase the product again (Kotler and Keller 2012, p. 136–137). Passengers preferences in regional and metropolitan transport are constantly changing (Kos et al. 2020). They are examined and discussed in the works of Dell’Olio et al. (2012) in relation to rail and road transport. Such comparison is a very important point of reference for deliberations included in this article as it shows that studies into the preferences of passengers for different kinds of transport are carried out in other countries as well.

The dissemination of the idea of sustainable development is an additional stimulus to take action inducing travellers to use public transport, with particular focus on rail transport. Companies competing in the passenger transport market must carry out a professional analysis of the market and customer preferences in order to provide the values most appreciated by customers. This is an opportunity for development of passenger rail transport, which is part of the sustainable development strategy. A special merit for further deliberations is presented by the work of de Oña et al. (2016a) with the title "Transit service quality analysis using cluster analysis and decision trees: a step forward to personalised marketing in public transportation," which demonstrates study results in relation to the group of "young adults," discussed further in the article. The examination of purchasing decisions taking into account the age criterion can be found in the study by Awad-Núñez et al. (2021), where the authors notice the specific nature of the decision-making process of young people above the age of 19. The importance of travellers’ age for decision-making manners has also been noticed by Kothari et al. (2016) and Branda et al. (2020).

International studies are a very good point of comparison, especially in terms of concept, methodology and international differences. However, one ought to note that every country’s market has its own determinants. Operators on the Polish rail transport market have to compete first of all with excessively developed private passenger car transport. The market is only now starting to be restricted by regulations on entry into city centres, higher parking fees and regulations counteracting congestion in urban agglomerations and air pollution. Rail infrastructure is being modernised and adapted to the European standards. Renovations conducted on a wide scale lead to slower train travels, train delays, the elimination of connections and information clutter. At the same time, amenities are being introduced for passengers, e.g. a single ticket for individual rail operators or carriers in different branches of transport, new forms of ticket distribution and replacing of train fleets with state-of-the-art ones. Travellers in other countries may not be familiar with all of the example barriers and impediments specified above. They can also significantly change the preferences of travellers, which are to be monitored constantly. The category of "young adults" selected for the study also results from an analysis of the offers of major operators in Poland, both on the rail and bus transport markets, with the main incentive being the diversification of services and prices for individual segments of travellers organised according to age, which could be seen in the studies by Kos et al. (2020) and by the Office of Rail Transport (2020). The innovativeness of the studies presented is based on the following premises:

  1. (1)

    They are focused solely on the group of young adults – people who travel often, who do not have their own cars, and who do not have established habits in door-to-door travelling. They also show the specific nature of that segment of travellers in Poland.

  2. (2)

    "Young adults" are a relatively rare object of study in terms of passenger transport, whether globally or in Poland. It is important to examine whether their preferences are significantly different from the preferences of all travellers treated as a whole. Such results are often presented in the available literature. The segment of "young adults" is changing very dynamically, their needs and preferences evolve in the process.

  3. (3)

    The studied sample, due to numerical strength and lack of other travelling habits, can become a key segment of travellers in Polish rail transport if proper marketing activities are implemented. This is an opportunity for changing the structure of transport in line with sustainable development of transport, especially after the pandemic which considerably increased the propensity of travellers towards using private cars.

This is also confirmed by the studies carried out by the Office of Rail Transport (https://utk.gov.pl/pl/dokumenty-i-formularze/opracowania-urzedu-tran/16097,Badanie-satysfakcji-pasazerow-kolei.html 2020) from April 17 to July 15, 2019 in the form of an interactive questionnaire at the website of the Railway Transport Office (RTO). The survey was conducted in Polish and addressed to passengers of all railway undertakings in Poland, who completed it using computers, tablets, or smartphones. The RTO initially sent a letter to the 14 largest railway passenger carriers in Poland, requesting that they disseminate information about the survey to passengers and interested parties, who care about improving the quality of railway services. The request was also sent to other entities, including Polskie Koleje Państwowe S.A. (Polish State Railways), PKP Polskie Linie Kolejowe S.A. (Polish Railways), which are the entities providing services in the area of rail passenger transport. It was also sent to the Marshals of all 16 provinces in Poland, which are organisers of the public collective transport system in the area of provincial rail transport. The involvement of local self-government centers in disseminating the questionnaire aimed to identify the needs of travelers and adapt transportation services to their expectations and budget resources. Many non-governmental organizations associated with railways or foundations working for the benefit of people with disabilities were also approached to spread information about the survey. As a result of these efforts, railway passenger carriers posted messages and hyperlinks to the survey on their websites and conducted direct information campaigns on social media platforms such as Facebook and Twitter. The Ministry of Investment and Development and the Centre for EU Transport Projects also supported the survey through an information campaign. Industry media outlets, including Rynek Kolejowy, Kurier Kolejowy, and NaKolei.pl, also contributed to disseminating information about the survey. A total of 5646 respondents completed the survey form. The largest group in terms of age included people at the age of 24–39 (49%). The majority of study participants were people travelling by rail every day (56.6%). In total, passengers commuting to/from work and school/university accounted for 71.8% of the respondents, which is significant from the point of view of analysing the study results. This is the group comprising the most loyal clients of railways, who – thanks to daily observations – indicate a lot of repeating factors affecting their rating of travel quality. On the other hand, those people are accustomed to some standards, which they treat as "normal" characteristics of the given transport operator, rail line, station, etc. Results of the above study also show the specific nature of the preferences of young travellers in Poland.

3 Research methodology

The study was carried out from October 2017 to March 2018 on a random sample of 350 individuals from all around Poland who met the requirement of age, thus forming the homogeneous group of "young adults" aged 18–29. The selected age bracket of respondents of above the age of 18 covers people who are adults by law and who can make decisions, drive a car and travel independently. However, the upper limit of the age bracket selected for the study was 29 years of age, which results from the features typical of Poland. In 2018, when the study was carried out, the respondents aged 29 or less were born after 1989, that is at the beginning of the political system transformation accompanied by the opening of Poland towards the influences of western countries. This is an entirely different generation in Poland, with new shopping patterns, new values and standards, new needs and preferences. Since then, a significant transformation in the economic, cultural and worldview spheres has occurred in Poland. Another premise for selecting this sample were analyses of the lifecycle of the Polish population. The available information shows that the age of 29 is the time of concluding marriages, starting long-term relationships, having children and finding a job that gives financial independence from the family. The age of 18–29 is also the age of the highest mobility – intense travelling connected with learning, studying, tourism and commutes to work. This is also facilitated by the absence of family obligations and an evident orientation towards self-fulfilment. Many people in this age bracket show highly varying transport behaviours – for instance, the absence of needing a driving licence. This age group accounts for ca. 20% of the total population in Poland.

The interviews were carried out in a direct manner. The research method included a survey. Respondents filled out a printed questionnaire. The surveys were carried out by selected individuals across Poland. An analysis of the filled-out questionnaires showed that 19 of them were incomplete. As a result, the sample of 331 respondents was qualified for further analysis. Yet, due to the nature of the study, the number of answers obtained by individual questions may vary. The study was qualitative and the results are representative for the studied group only. However, their value must be stressed due to the general reluctance of individuals from this age group to participate in studies. Having included some significant topics for the respondents, it will be possible to formulate a questionnaire and carry out representative studies on a wide scale. The study covered regional and metropolitan transport.

Table 2 presents characteristics of the respondents based on detailed information provided by them.

Table 2 Respondents' socio-demographic characteristics (N = 331)
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The purpose of the study was to define the preferences of young respondents, which involved assessing the importance and quality of services offered by passenger rail transport operators and public road (bus) transport operators.

The survey questionnaire included study areas regarding price, duration and modern technologies. In order to achieve the intended aim of the article, an attempt was made to answer the following research questions:

  1. (1)

    What is the importance of characteristics of the services provided by carriers in passenger rail transport and collective road transport (bus transport) in the context of actions related to the categories of price, time and modern technologies?

  2. (2)

    What is the rating of characteristics of the services provided by carriers in passenger rail transport and collective road transport (bus transport) in the context of actions related to the categories of price, duration and modern technologies?

The following hypothesis was formulated: The more important the given characteristic of the service to the respondent, the higher its rating.

The category of price in passenger rail transport included the guarantee of refunds due to delays, price promotions and ticket price. The category of duration of passenger rail travel included the duration of travel, number of transfers, convenient connection times, number of connections, punctuality of trains. The category of modern technologies in passenger rail transport included the possibility of tracking information on social media during travel, providing additional Wi-Fi services, checking train connections on the Internet, having a ticket in the electronic form during travel, buying tickets on the Internet, buying tickets with mobile devices and tracking the route and location of the means of transport during travel via a mobile application.

Answers available to the respondents included: “very important”, “important”, “less important”, “unimportant” and they used the following rating scale: “very good”, “good”, “bad”, “very bad”.

In order to answer the research questions and test the hypothesis, statistical analyses were carried out using the IBM SPSS Statistics version 25. It was used to analyse basic descriptive statistics, to analyse linear correlation by means of Pearson's r test and Spearman's rho test, and to compare dependent pairs using the t test for dependent samples and Wilcoxon's non-parametric test. The classical threshold of α = 0.05 was designated as the significance level. The probability results of the test statistics at the level of 0.05 < p < 0.1 were interpreted as significant at the level of the statistical trend.

4 Research results

An analysis of the respondents’ answers allowed the following conclusions:

Basic descriptive statistics of the measured quantitative variables with a normality test:

First of all, it was verified whether there were any observations in the data set which deviate from the median. It was found that there were many outliers in the database, the removal of which would result in a significant reduction in the number of respondents and loss of valuable data. For this reason, the decision was made to retain all but two observations in the case of which, as it was established, respondents answered the questions in the same manner. Therefore, results of the respondent who marked maximum values and of the respondent who marked minimum values in all questions were removed from the database.

Then, descriptive statistics of all the variables on the quantitative scale were verified using the Shapiro–Wilk test to analyse a normal distribution (Table 3).

Table 3 Descriptive statistics in regional and metropolitan transport
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Results of the Shapiro–Wilk test indicated that none of the quantitative variables had a normal distribution (p < 0.05). Since the skewness and kurtosis of most of the variables were in the range of – 2 and 2, the author concluded that the absence of a normal distribution in their case did not bias the parametric tests excessively. However, in the case of variables, the importance of prices and travel time in passenger rail transport was observed to deviate from a low kurtosis and asymmetry; therefore, non-parametric tests were adopted in analyses with these two variables. Respondents answered questions using a rating scale that ranged from “very good” (minimum), “good”, “bad”, to “very bad” (maximum).

4.1 The price importance in public road transport and public rail transport

The first step involved the examination whether the price was equally important for the respondents in bus transport and passenger rail transport. To compare dependent pairs, the Wilcoxon non-parametric test was used due to a high kurtosis of the price significance variable in passenger rail transport. In addition, Hedges' g measure was used to estimate the strength of the difference. The obtained results are presented in Table 4.

Table 4 Price importance in public road transport and public rail transport
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The results of the Wilcoxon test indicated that the importance of prices in public road transport and in passenger rail transport was significantly different. According to the respondents, prices were more important in bus transport than in passenger rail transport. Hedges' g score indicated large differences between variables, exceeding the threshold of a large effect size (g > 0.8). The differences between the variables are depicted in Fig. 1.

Fig. 1
figure 1

Source: own study

Price importance in public road transport and passenger rail transport.

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4.2 The importance of travel time in public road transport and passenger rail transport

The next stage involved an analysis of the question whether there was any difference between bus transport and passenger rail transport in terms of travel-time importance. The analysis was carried out using the Wilcoxon signed-rank test due to the large skewness and kurtosis of the importance of travel time in passenger rail transport. Hedges' g statistic was used again to assess the strength of the difference. The analysis results are presented in Table 5.

Table 5 Importance of travel time in public road transport and passenger rail transport
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The analysis did not reveal a statistically significant difference between passenger rail transport and bus transport. The respondents reported that travel time was equally important both in passenger rail transport and public road transport. The variables are presented in Fig. 2.

Fig. 2
figure 2

Source: own study

Importance of travel time in public road transport and passenger rail transport.

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4.3 The importance of technical equipment in public road transport and passenger rail transport

Using the Student’s t-test for dependent samples, a comparative analysis of the importance of modern technology in passenger rail transport and bus transport was carried out. Due to the skewness and kurtosis between – 2 and 2 as well as the quantitative nature of the variables, the decision was made to use the parametric test. To determine the effect size, Cohen's d value was determined. Table 6 presents results of the calculations performed.

Table 6 Importance of latest technical equipment in public passenger road and rail transport
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Statistically significant differences between public road transport and passenger rail transport were noted regarding the respondents’ opinions on the importance of modern technology. Modern technologies were considered more important in bus transport than in passenger rail transport. However, when interpreting the effect on the basis of Cohen’s d, one has to consider that the difference has not reached a small size (d < 0.2). Figure 3 shows the means with the standard deviation of both variables.

Fig. 3
figure 3

Source: own study

Importance of latest technical equipment in public road transport and passenger rail transport.

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4.4 Rating current prices in public road transport and passenger rail transport

An analogous test was used to examine the differences between public road transport and passenger rail transport regarding the rating of current prices. Due to variables on the quantitative scale with a low kurtosis and skewness, the parametric test was used in this case as well. Results of the analysis are presented in Table 7.

Table 7 Rating of current prices in public road transport and passenger rail transport
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Rating current prices differs as well between the passenger rail transport and public road transport. In this case, the difference is considerable (d > 0.8). The respondents rated the current prices in passenger rail transport higher than in bus transport. The differences are presented in Fig. 4.

Fig. 4
figure 4

Source: own study

Rating of current prices in public road transport and passenger rail transport.

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4.5 Rating travel time in public road transport and passenger rail transport

Student's t-test for dependent samples was used again to determine whether there is a difference between bus transport and passenger rail transport regarding the rating of travel time. The values of asymmetries and the kurtosis of both variables did not affect the analysis result. Additionally, the travel time both in public road transport and in passenger rail transport was assessed on a quantitative scale. Since the parametric test was used, the decision was made to calculate Cohen's d measure when determining the effect size. Results of the calculations are presented in Table 8.

Table 8 Rating of travel time in public road transport and passenger rail transport
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Differences at the level of the statistical trend between public road transport and passenger rail transport were observed. It is worth noting that Cohen’s d did not reach the small effect size (d < 0.2), which would mean a minor difference between the variables or its absence in statistical terms. Bus transport scored slightly higher than passenger rail transport in terms of travel time, as may be seen in Fig. 5.

Fig. 5
figure 5

Source: own study

Rating of travel time in public road transport and passenger rail transport.

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4.6 Rating the latest technical equipment in public road transport and passenger rail transport

In the next stage, bus transport was compared with passenger rail transport in terms of rating of the latest available technical equipment used. Calculations were made using the Student's parametric t-test for dependent samples, taking into account the quantitative nature of variables as well as the skewness and kurtosis between – 2 and 2. Results of the test with Cohen's d measure are presented in Table 9.

Table 9 Rating of latest technical equipment in public road transport and passenger rail transport
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It was found that the respondents had assigned a higher score to the technical equipment currently used in public road transport than in passenger rail transport. The difference was statistically significant and was at a medium level (0.5 < d < 0.8). The results are presented in Fig. 6.

Fig. 6
figure 6

Source: own study

Rating of the latest technical equipment in public road transport and passenger rail transport.

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4.7 Rating of services offered by public road transport operators and passenger rail transport operators

Finally, the respondents’ opinions on services offered by bus and train operators were compared. In this case as well, the skewness, kurtosis and the type of variable scale allowed the performance of the parametric test – t test for dependent samples. The results of the analysis are presented in Table 10.

Table 10 Rating of services offered by public road transport operators and passenger rail transport operators
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Services offered by bus operators were rated higher than services provided by passenger rail operators. The difference in ratings was statistically significant, and Cohen's d measure indicated a small effect (0.2 < d < 0.5). Mean variables with error bars are depicted in Fig. 7.

Fig. 7
figure 7

Source: own study

Difference between public road transport and passenger rail transport in terms of rating of currently offered services.

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4.8 Relationship between the importance of prices in passenger rail transport and their rating

In the next step, correlations between the importance of prices in passenger rail transport and their rating were examined. Since the variable “importance of prices in passenger rail transport” had a large kurtosis (2 < Kurt.), the decision was made to use non-parametric Spearman’s rho test to verify the interdependence of variables.

The analysis failed to indicate any statistically significant correlation between the variables (rs = – 0.01; p = 0.810; N = 286). This means that the respondents rated the current prices of passenger rail services regardless of the importance they attributed to them. The dispersion of the results along with the trend line is depicted in Fig. 8.

Fig. 8
figure 8

Source: own study

Relationship between the importance of prices in passenger rail transport and rating thereof.

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4.9 Relationship between the importance of travel time in passenger rail transport and its rating

In the next step, the relationship between the importance and the rating of travel time in passenger rail transport was analysed. The correlations were examined using a non-parametric test due to excessive skewness and the kurtosis of the importance of travel time in passenger rail transport.

The relationship between the variables was statistically insignificant (rs = 0.06; p = 0.308; N = 285). Survey participants considered the time of travel in passenger rail transport important, regardless of how they assessed its current state. The results of the analysis are presented in Fig. 9.

Fig. 9
figure 9

Source: own study

Relationship between the importance of travel time in passenger rail transport and the rating of the current travel time.

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4.10 Relationship between the importance of the latest technical equipment in passenger rail transport and its rating

The last characteristic of passenger rail transport, for which correlations between the importance attributed by the respondents and the assigned rating were examined, was the latest technical equipment. In this case, both variables had a quantitative scale as well as the skewness and kurtosis between – 2 and 2; therefore, Pearson’s r parametric test could be performed.

The analysis indicated a linear, statistically significant correlation between the opinion on the importance of modern technologies in passenger rail transport and the rating regarding their current state (r = 0.74; p < 0.001; N = 268). The interdependence of the variables was strong and positive, which meant that the higher the rating of state-of-the-art technical equipment used in passenger rail transport, the greater the importance that was attributed to it by the passengers. The relationship between the variables is depicted in Fig. 10.

Fig. 10
figure 10

Source: own study

Relationship between the importance of the latest technical equipment in passenger rail transport and the assessment of their current state.

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4.11 Relationship between the importance of prices in bus transport and its rating

In the next step, correlations in public road transport were examined more closely. First, the author analysed whether there was a correlation between the importance of prices and its rating. For this purpose, the decision was made to perform Pearson’s parametric r test due to the quantitative variable scales, the small kurtosis and skewness.

The results suggested that there was no interdependence between the importance attributed to prices in bus transport and their rating (r = – 0.2; p = 0.744; N = 257). When rating current prices in public road transport, their importance was not relevant. Both the dispersion of data and the trend lines of the relationship tested are depicted in Fig. 11.

Fig. 11
figure 11

Source: own study

Relationship between the importance of prices in bus transport and the rating of current prices.

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4.12 Relationship between the importance of travel time in bus transport and the rating of current travel time

Pearson's linear correlation r test was used to investigate the relationship between the importance of the travel time in public road transport and the rating of the current travel time. The decision was made to use the parametric test as the variables met the conditions for the quantitative scale, skewness and kurtosis in the range from – 2 to 2 and, therefore, they did not bias the analysis excessively.

No statistically significant correlation was observed between the analysed variables (r = – 0.14; p = 0.019; N = 264). The respondents assessed the importance of travel time in bus transport without referring to the rating assigned to this characteristic. The result is presented in Fig. 12.

Fig. 12
figure 12

Source: own study

Relationship between the importance of travel time in bus transport and the rating of current travel time.

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4.13 Relationship between the importance of the latest technical equipment in bus transport and its rating

Finally, the author analysed whether the importance of the latest technical equipment in bus transport was related to the respondents’ rating of its current state. For this purpose, Pearson’s parametric linear correlation r test was also used, as the variables had a quantitative scale and were characterised by a low skewness and kurtosis. The interdependence of variables is presented in Fig. 13.

Fig. 13
figure 13

Source: own study

Relationship between the importance of modern technology in bus transport and rating of its current state.

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The results confirmed the interdependence between the importance attributed to the latest technical equipment in bus transport and the rating of its current state (r = – 0.08; p = 0.213; N = 263). The relationship between the variables was weak and negatively oriented. Respondents who rated the latest technical equipment in bus transport higher attached less importance to it.

Studies among young travellers have shown that the process of limiting road (bus) transport is slow and it encounters many barriers and limitations. They included two elements – the importance and the rating of the implemented features. In the area of importance – the respondents determined that the prices and modern technologies were more important in bus transport than in passenger rail transport and that the travel time was of similar importance in passenger rail transport and collective road transport. From amongst the detailed features, they indicated the most important one of the ones specified in the study – convenient connection times. As far as the price is concerned – the respondents evaluated the prices in passenger rail transport much higher than in bus transport; they rated the current duration of travelling by bus slightly higher than in passenger rail transport as well as evaluated the latest technical equipment used in collective road transport much higher. Overall, they evaluated the services offered by bus higher than the services offered by passenger rail transport. Along with a higher rating of the latest technical equipment applied in passenger rail transport, the respondents attributed a higher importance to it; what is more, the higher the rating score for the latest technical equipment in bus transport, the lower its importance.

5 Discussion

In the studies presented in the article, costs, time and the latest technical equipment were adopted for the purpose of assessing the preferences of young passengers. The choice resulted from an analysis of the available literature, both Polish and foreign. The same or similar categories of preferences can be found in many publications. A review of the literature and available research shows that passengers make decisions related to selecting the means of transport in conditions of uncertainty (Enoch 2020). Variables known to the passenger at the time of making the decision usually include the travel cost, departure time and possible travel time. Passengers' preferences have also been investigated by many authors around the world, for instance: Froidh and Bystrom (2013), Paha et al. (2013), Tsafarakis et al. (2018), who observe the habits and emotional attitude of passengers towards the operator. The authors emphasise that the decisions of passengers are affected by transport-related routine and customary behaviours of passengers based on their experience (Paha et al. 2013). Many authors emphasise that preferences developed on this basis usually focus on time and price (travel costs) as well as their components (Rosa 2020; Kos et al. 2020; Badanie satysfakcji…, 2020; Krawiec and Ćwiek 2019). Categories of passengers' preferences most frequently referred to in literature include (cf. Rosa 2021):

  1. (1)

    Costs (ticket prices, price discounts) (Kos et al. 2020; Branda et al. 2020)

  2. (2)

    Time (short waiting time, short travel time, convenient connection times, frequency of connections) (Badanie satysfakcji…, 2020; Kos et al. 2020),

  3. (3)

    Travel convenience, comfort comprising (Badanie satysfakcji…, 2020; Kos et al. 2020),

  4. -

    Purchase of tickets and related passenger's experience (Brumercikova et al. 2020; Branda et al. 2020),

  5. -

    Personal safety regarding all stages of the journey (Bolobonov et al. 2021; Hlavatý and Ližbetin 2021),

  6. -

    Quality of experienced carriage services in multiple aspects regarding: stations, platforms, vehicles, train service, travel conditions (Antonowicz and Bogucka 2019; Kos et al. 2020; Abramovic and Sipus 2019),

  7. -

    Passenger's emotional attitude towards railways (Froidh and Bystrom 2013; Paha et al. 2013; Tsafarakis et al. 2018; Enoch 2020),

  8. -

    Railway accessibility for disabled passengers (Froidh and Bystrom 2013),

  9. -

    Quality of service provided by the railway personnel prior to, during and after the journey (de Oña et al. 2014; Eboli and Mazzulla 2015; Mazzino 2017; Eboli et al. 2018; Antonowicz and Bogucka 2019; Kos et al. 2020),

  10. -

    Passenger information system via all channels (Hlavatý and Ližbetin 2021).

However, the studies and presented results most commonly regard all segments of passengers and do not differentiate the specifics of young passengers. A confirmation of the results of the presented research may be found in the paper by de Oña et al. (2016b), where the authors refer to the group of passengers, including ‘young adults’. They also notice differences in the preferences of this group of people for whom punctuality of the means of transport is the most important criterion, which corresponds to their travelling destination – work or school/university. An investigation of passengers’ purchase decisions taking into consideration the age criterion can be found in the paper by Awad-Núñez et al. (2021) where the authors notice the specifics of decision making by young persons who have attained the age of 19. The significance of the passengers’ age for the decision-making process is also emphasised by such authors as Kothari et al. (2016) and Branda et al. (2020). The generational difference between the passenger segments in Poland is also reflected in young people’s perception of the car as a "tool" for commuting and not a synonym of wealth. Many young people notice issues in incurring the costs of fuel, parking, insurance and maintenance of the car and, thus, prefer public means of transport. The preferences of this group differ slightly from those of other age groups. The travel time is effectively used. Young adults appreciate online contact, social media presence, reading and learning while travelling. That is possible only in public transport, while travelling as a passenger, especially in railway transport. The approach of this segment towards individual transport matches the idea of sustainable development. The main reasons pointed to by all passengers when choosing the passenger car to commute to work or school instead of public transport is an excessive distance to the nearest public transport stop / station, a lack of appropriate connections in the public transport timetable as well as long travel times in public transport (Badanie pilotażowe…2019). Similar results are presented in the passenger satisfaction study carried out by the Office of Rail Transport (https://utk.gov.pl/pl/dokumenty-i-formularze/opracowania-urzedu-tran/16097,Badanie-satysfakcji-pasazerow-kolei.html 2020; Rosa 2021). The survey results presented by the author align with another survey conducted by the Railway Transport Authority in their report titled 'Passenger Satisfaction Survey—Edition II' (2022), which received responses from 1516 participants. The survey included two key questions. The first question asked respondents to identify the factors that influence their choice of rail travel, with the most frequently cited factors being travel time (55.8%), travel comfort (41.6%), and ticket prices (35.2%). Respondents rated these features highly. However, respondents rated the adaptation of train lengths to the actual traveler attendance (49.4%) and the availability and quality of internet on trains (51.5%) as low (bad and very bad). The second key question asked respondents about the measures that operators should take to encourage travelers to return to railways once the COVID-19 pandemic has ended. Respondents identified improving the transport offer (77.6%), reducing congestion on trains (55.7%), and reducing ticket prices or offering promotions (43.9%) as the most important factors (https://utk.gov.pl/pl/dokumenty-i-formularze/opracowania-urzedu-tran/19585,Badanie-satysfakcji-pasazerow-kolei-2021.html 2022). Another confirmation is provided by detailed results of the qualitative studies presented in the article which showed that convenient connection times (most important feature) are the most important for young people. The studied categories (price, time and modern technical equipment) comprise several components (the scope of the studies was significantly broader and deeper than presented in this paper) which should be analysed in detail in terms of the cause of the higher performance rating in the case of bus transport. It is crucial due to the focus of passengers' preferences on railway transport as more environmentally-friendly and preferred in the idea of sustainable development of transport.

6 Conclusion

The study results indicate that convenient travel connection times are of greater importance to young travelers, which are strongly linked to travel time, which is equally important. Moreover, modern technical equipment is highly valued among young travelers. Comparatively, road transport was perceived as a more favourable option than rail transport among young travelers in Poland. To promote sustainable transport development, it is suggested to take a two-stage approach:

  1. (1)

    Encourage travelers to use public transport and incorporate changes to improve the road and rail transport offer based on the respondents' preferences,

  2. (2)

    Encourage travelers to use rail transport, which is more environmentally friendly and in accordance with the survey results, additional changes should be implemented in areas where rail transport lags behind road transport.

Further studies related to passenger rail transport should focus on a comprehensive analysis of the travel time and price policy, i.e. categories comparable or superior to road transport. An essential criterion, especially for young people, are modern technologies that should also be analysed and implemented by the carriers. Extending the offer in this scope is important for young passengers. The next step of studies should be an extension of the research area and the inclusion of private transport. Identifying the preferences of young passengers is crucial, especially as regards factors that will make them give up private cars and switch to rail transport. Rail transport operators should develop a strategy regarding travel-time elements – punctuality, frequency of connections, convenient departure times, effective use, etc., adjusted to the segment of key customers that "young adults" are becoming. The above system research may contribute to an effective shaping of young passengers’ preferences and an increase in rail passenger transport, as it arises from the idea of sustainable development of transport. This approach is likely to yield results in the coming years as young people develop habits and routines around using public transport and transition to older age segments.