5.1. Survey Analysis
As previously mentioned in Section 3.2
, a web-based survey was conducted in order to characterise and quantify observed and latent variables of travel and life satisfaction of L6 users of Metro de Santiago. The survey was conducted through an on-line questionnaire in June 2018, and 271 complete responses were received. A comparison of some socio-demographic attributes of respondents of this research survey and previous origin-destination survey conducted by Metro de Santiago in its network in 2017 is shown in Table 5
The results showed that the L6 survey was highly biased towards male respondents (68%), compared to the Metro survey in 2017 (45%). This result was expected due to the nature of the survey applied, as male respondents are more willing to answer an on-line questionnaire than women, although the Metro survey was also biased as female respondents were more willing to answer an on-site questionnaire at stations than men. Furthermore, the same effect of on-line versus on-site survey application could be seen regarding differences in the young population (18–30 years) against adults (31–60 years) and high-income households (more than EUR 1768 monthly) against middle-class households (EUR 408–1088). However, in the latter dimension, 28% of Metro survey respondents preferred not to answer this question, and the income distribution of Metro users remains an open issue today. It should be noted that these effects are some specific issues observed before in the Metro, regarding previous surveys and its responses rates, and does not represent a generalisation of survey applications.
Although the survey applied has important differences with respect to the Metro survey in terms of sample socio-demographic characteristics, it is still useful to make an inference about which attributes were mediating satisfaction with travel and global well-being.
Regarding the results of satisfaction with travel in the L6 user survey, in Figure 9
, trip perception aggregate scores for each attribute are shown. Furthermore, the standard deviations of each variable are displayed in Table 6
. The survey was specifically designed to reflect good perceptions regarding each attribute through higher scores (e.g., a high score in the crowdedness
attribute means that the respondent was perceiving a low density inside the train). Consequently, crowdedness, complementary uses of travel time (such as reading a book or using a mobile phone when travelling) and security were the most valued perceived satisfaction attributes for L6 users. In-vehicle travel time was only the fourth most valued attribute, with an average score of 3.95 on a scale of 1–5. Nevertheless, the set of attributes proposed had a high score in general, as all attributes were ranked in the upper half of the scale on average. Only waiting time had a relatively low average score, equivalent to 3.18. This could be explained as due to the low frequency of L6 trains compared with the rest of the Metro network. For instance, L6 operated in its first year with an interval of 4.0 min in peak hours, but other lines reached intervals between 1.5 and 2.5 min in the same period. Furthermore, it is likely that stations’ design and intermodality/transfer dimensions obtained a comparatively low score due to the depth of L6 tunnels and platforms, constructed below the existing network of the Metro, which require that passengers must use an important amount of time on stairs, escalators or elevators in order to enter or exit stations.
On the other hand, in Figure 10
, STS scores obtained in the L6 user survey by each dimension are displayed, namely six affective and three cognitive scales. Regarding affective dimensions, enthusiastic
obtained relatively high scores, possibly due to the novelty that is implied by a new line of the Metro, the first with an unattended train operation in Santiago. Relaxed
appears with a slightly relatively low score, possibly due to the inexperience in the first months of the use of the new line, and also, respondents declared using this line more during peak hours (56%), where people are inclined to have fixed appointments regarding work or study activities, increasing anxiety. Furthermore, cognitive dimensions obtained relatively high scores, revealing that users had some valuable opinions of the Metro infrastructure related to non-affective and long-term issues.
In relation to global well-being and SWLS results, Figure 11
shows that L6 users were satisfied with their lives in general. Scores were quite flat across all five statements, with an average of 3.63. Only statement SL4, regarding overall conditions of life, obtained an score of 3.83, slightly above the average. However, if respondents are disaggregated by age groups an interesting effect occurs, as shown in Figure 12
, where respondents below 18 years and above 60 years were discarded due to low response rates in the sample. All five satisfaction-with-life statements were consistently less rated in adults (31–60 years) than in young people (18–30 years). Furthermore, this effect is clearly visible in statement SL5, related to life changes if they would have the opportunity to live their life over again. These findings are consistent with previous studies that had found evidence of a U-shaped relationship between well-being and age [44
], where the minimum satisfaction of life occurs around middle age (35–50 years).
5.2. Model Results
Using a confirmatory factor analysis (CFA) approach, applied to the L6 user survey, a construct was designed and modelled in order to reveal which observable variables were mediating in satisfaction with travel and life, respectively, as detailed in Section 3.2
. A particular emphasis in the in-vehicle travel time was made, trying to find to what extent this variable was relevant to both latent satisfaction dimensions.
First, relevant goodness of fit indices for CFA models are described in Table 7
. In this case, the construct proposed had a goodness-of-fit index (GFI) of 0.675 and a root mean squared error of approximation (RMSEA) of 0.096. Therefore, this specification is in the threshold of an acceptable fit, accordingly to the RMSEA index in particular.
On the other hand, standardised effects of observed variables on travel and life satisfaction are shown in Table 8
, where for the sake of simplicity, only significant effects are displayed. Regarding satisfaction with travel, waiting time, stations design, safety and intermodality were mediating this variable, and in general, observing the standardised coefficients, the effects of each of them were all rather similar. However, in-vehicle travel time was not correlated with travel satisfaction. Recalling perception scores in the survey, shown previously in Figure 9
, this variable obtained a high average score anyway. Both facts could be interpreted as that even if in-vehicle time is highly valued by L6 users, users are taking travel time savings for granted in the case of the Metro. In the context of a more complex public transport network considering other modes, in-vehicle travel time does not mediate satisfaction with travel. Furthermore, crowdedness, complementary travel time use and security were not correlated with satisfaction with travel either, although these variables were highly scored by users as well. However, in this case, the variances of these variables across the sample were rather low, as reflected in the standard deviation results in Table 6
for all four variables. Therefore, the model was not able to capture any effect caused by these variables.
In relation to socio-demographic variables, household size has a negative influence on travel satisfaction, although this influence is marginal. Presumably, the probability of users with greater household sizes travelling with other members of the same family together, such as parents travelling with little children, is high in these cases. This fact makes the mobility inside the Metro network more difficult. Besides, age had a positive influence on satisfaction with travel, revealing that older people were more satisfied with the Metro service than young people. However, as this variable is only significant at the 0.10 level and the sample of elderly people (above 60 years) was limited in this survey, this presumption must be made carefully, and further research and data to address this particular issue are needed.
In terms of trip attributes, the period of use and fare were the only variables that had a significant influence on satisfaction with travel. In the case of period, travelling outside of peak times increased travel satisfaction as expected, as the crowdedness was less in this period. Also expected, fares had a negative effect in travel satisfaction, as groups such as students and elderly people had concessionary fares in the Metro network, and therefore, these groups were more satisfied in relation to travel.
Regarding life satisfaction, this latent variable was highly mediated by household income in the first place. In a highly unequal society such as Chile [46
], the lack of accessibility to effective social rights such as good health or education caused disposable income to determine strongly the quality-of-life of the population. Rather surprisingly, gender had a relevant influence on life satisfaction as well, revealing that women were more satisfied than men overall. Further research is needed in order to clarify which are the personal and social characteristics that are influencing this result in the Chilean context.
Furthermore, aggregate travel satisfaction was also influencing life satisfaction, revealing that day-to-day urban transport issues were mediating overall quality-of-life, and consequently, mobility was an important dimension in the context of Santiago. However, other dimensions of mobility had a direct and noteworthy influence on life satisfaction as well. For instance, in-vehicle time and intermodality, which reflect to some extent the quantity of daily time assigned by each person to mobility purposes. Physical conditions between different transport modes in relation to Metro stations was highly influential on its own. Both had an effect almost equal to aggregate travel satisfaction, revealing particularly that travel conditions mediated global well-being. Unexpectedly, waiting time had a significant and negative correlation with life satisfaction. A logical explanation of this effect, and a negative influence of this variable in particular, is not possible at this stage, given the limitation of data of the survey applied.
Besides, the period of use of L6 had a significant effect on life satisfaction. Likely, people travelling outside of peak hours had more flexibility in their daily routines, as they did not have fixed appointments at peak hours when the Metro network (and the transport system in general) was highly congested, increasing overall quality-of-life.
Finally, in Table 9
, the standardised effects of travel and life satisfaction on observed indicators of STS and SWLS are presented, showing that the observed variables of both scales were highly useful to represent latent variables for travel and life.
All previously-mentioned issues are relevant at the planning and design stages of future public transport projects, and in the appraisal processes in new Metro infrastructure development in particular. In-vehicle travel time (as a proxy of travel time savings) was highly valued, but taken for granted by users in the case of the Metro, as analysed before. Nevertheless, other remarkable issues arose from the survey analysis. First, overall travel satisfaction had an effective correlation with life satisfaction, revealing that public transport by Metro was an influential dimension in Santiago’s urban life. However, to what extent transport was relevant in the context with other life dimensions, such as family conditions, health, work or education, is out of the scope of this research. However, even if urban mobility is a daily-based activity and public transport is continuously mentioned as one of the priorities in which the government should invest time and resources, Chileans still declare that solving street crime, retirement pensions, public health and education are more urgent than other issues [48
]. This could constitute a barrier to attract relevance to public transport projects in a political dimension in the local context. Second, specific variables concerning urban transport were influential in both travel satisfaction and life satisfaction, and should be included in future project appraisal processes, aiming to increase the quality-of-life of the population. For instance, waiting time relevance could lead to defining a standard in the supply, namely service frequency, of public transport routes, which today are mostly adjusted to the demand in Santiago. This causes that in certain routes with low demand, low frequency services are supplied, and waiting time increases proportionately, decreasing travel satisfaction. Besides, a particular focus on stations’ design and intermodality should be considered in future Metro projects. Considering that new lines must be constructed increasingly deeper in the city, usefulness for users should be put in the centre of the physical design stages, thinking about how elements such as ticket machines, turnstiles, escalators, stairs, elevators, platforms and trains are contributing to seamless travel inside the Metro network, and how the urban train provides integration with other modes, an issue that today is not generally considered during the appraisal and design stages. Finally, a disaggregation of potential users should be considered in future Metro projects. Gender, age, household income or household size influenced travel and life satisfaction, revealing that people with different characteristics had a different viewpoint about the transport system. Nevertheless, the appraisal processes today in Chile assume that an average person
exists, which given the evidence of this article’s results, is not supported.