1. Introduction
The rise of mobility-on-demand platforms is one of the most important innovations of recent decades. Ride-sourcing, transportation network companies, and on-demand rides [
1] are among the precursors of a sharing economy [
2]. While there are various terms for mobility-on-demand platforms, this study defines ride-sourcing as application-based services provided commercially by companies [
1]. These services match travellers who want to take a specific trip, through a mobile application, with a driver who is willing to satisfy that demand in real-time [
3,
4,
5]. The magnitude of the growth in ride-sourcing in various countries around the world has been extraordinary [
2]. Due to its position as one of the countries with the highest smartphone ownership rates in the world and continuous developments in terms of Information and Communication Technology (ICT) infrastructure [
6], the increase in ride-sourcing users can be observed in Indonesia. Go-Jek, founded in 2010, was the first ride-sourcing service in Indonesia and is currently present in 50 cities there. It facilitated 5 billion kilometres of travel in 2019 [
7,
8]. The poor networks and poor quality of public transport systems in developing countries [
2] mean that ride-sourcing services have a role in supporting the public transport system, particularly in Indonesia [
9,
10]. In Indonesia, there are two types of ride-sourcing services, namely motorcycle- (MBRS) and car-based ride-sourcing (CBRS). The users of these two types of ride-sourcing modes might have differences in perceiving the usefulness of the services and different usage behaviours. There is an indication that MBRS is used more often by low-income persons, which may make their use of the services less frequent than CBRS users [
9]. With this strong growth and strong implications for providing better mobility, the investigation of ride-sourcing services in developing countries is worthy of being conducted.
Studies [
11,
12] have identified the various benefits of ride-sourcing over public and private transport, such as having the flexibility of private modes of transport without the additional effort of finding parking lots and paying parking charges, or in the case of public transport, having less egress, ingress and waiting time [
13,
14,
15]. Ride-sourcing studies have focused on mode choice or whether users choose ride-sourcing as a substitute for public or private modes of transport or as a complement to public or private transportation. Ride-sourcing has been found to be used as a substitute for the feeder systems of public transport (e.g., Light Rail Transit/LRT and bus system), but it increases the use of primary systems of public transport [
16]. Other studies argued that ride-sourcing complements secondary and/or feeder systems in developed [
17,
18] and developing countries [
9,
10]. The growing number of ride-sourcing users causes researchers to study factors related to the frequency of using the services [
11,
12,
19]. Socio-demographic variables (e.g., income, age, employment, education, and race), land use, the built environment, the use of the internet or social media, and instrumental variables (e.g., frequency of long-distance trips) were used as predictors of ride-sourcing usage, whilst non-instrumental factors have also been proposed to correlate with mode choice [
20,
21,
22,
23,
24]. Alemi et al. [
11] have included attitudes in the frequency of the use of ride-sourcing. On the other hand, Dawes et al. [
25] and Irawan et al. [
9] used the benefits of using ride-sourcing (e.g., the perceived ease of use of the applications, perceived shorter travel time, no ingress and egress, comfort, safety, and environmental benefits) on ride-sourcing usage.
Among the non-instrumental factors, some studies have shown the effects of travel experiences on the mode choice [
26,
27], but, to the best of the authors’ knowledge, travel experiences have rarely been used as a predictor in ride-sourcing studies. Similar to public transport, travelling with ride-sourcing includes on-journey (e.g., travel and waiting time) and before-journey (e.g., reliability of the applications and the service coverage area) components, whereas before-journey components are not found when taking private vehicles. The high penetration of ride-sourcing might be due to the reliability of before-journey components, for example, calling the service just using a smartphone, compared to the greater effort involved in taking conventional taxis and public transport. Informal community drivers who share their vehicles with passengers via mobile applications may increase the coverage of the services compared to conventional taxis and public transport. It is hypothesised that the before-journey advantages are the reason why this mode is perceived to be useful and why travellers use this mode more often. Circella and Alemi [
28], Rayle et al. [
1], Tang et al. [
29], and Tirachini et al. [
2] have suggested some on-journey and before-journey advantages of using ride-sourcing, but without detailed classifications of whether these are before- or after-journey advantages and without advanced statistical tests. This study tries to adjust the various on-journey and before-journey advantages of using ride-sourcing to be more relevant in the Indonesian context, as modified from Tirachini et al. [
2], and thus to apply it by using multivariate analysis.
Using data collected from ride-sourcing users in Bandung City in 2018, Exploratory Factor Analysis (EFA) is used to explore the typology of various positive and negative experiences using ride-sourcing, and these will be used as predictors of the perceived usefulness of ride-sourcing. Assuming that it has a structural form, the study assumes that the effects of the perceived usefulness of ride-sourcing correlate with ride-sourcing usage. The typology of various positive and negative travel experiences is expected to differentiate which components are part of on-journey and before-journey benefits and drawbacks. This may help in understanding which components correlate with the usefulness of the service and its usage. This study will also use socio-demographic and travel characteristics, the built environment, and multiple types of multi-tasking activities in interaction with various positive and negative travel experiences on those two dependent variables. The inclusion of socio-demographic, travel characteristics, and built environment variables will help suggest the persons that should be targeted for using the modes more frequently. In Indonesia, pool ride-sourcing is available for CBRS, but the service is not popular. Therefore, this study will focus on the non-pooled services of CBRS and MBRS. Due to a number of sampling problems with CBRS users, this study does not separate the perceived usefulness and ride-sourcing usage into CBRS and MBRS models. This study only uses a dummy variable for indicating whether the respondents are MBRS or CBRS users. The dummy variable can indicate whether MBRS and CBRS users have different perceptions of usefulness and ride-sourcing usage. The modified Structured Equation Model (modified SEM; [
20,
30]) is used for its flexibility in examining different responses of endogenous variables in the recursive structure with less computational time, but it ignores the reciprocal effects as a limitation of the model. In this study, perceived usefulness is treated as a continuous variable, whereas the frequency of using ride-sourcing is treated as an ordinal response.
The remainder of the paper is structured as follows. The following section presents the literature review, while the data collection and the respondents’ characteristics are described in the data explanation section.
Section 4 explains the model structure. The model estimation is presented in
Section 5, followed by the discussion and conclusion sections.
4. Proposed Model Structure
To better understand the relationships between the perceived usefulness and the frequency usage and what describes those variables, the interaction between socio-demographic, travel, multi-tasking, built-environment, on-journey and before-journey advantages, and travel disadvantages were modelled using the modified SEM.
Figure 2 shows the proposed model. Perceived usefulness and frequency of usage were analysed in the models as endogenous variables, while all the other variables were treated as exogenous.
The modified SEM captured the relationship between the perceived usefulness and the frequency usage in a recursive structure. Full-information Maximum-Likelihood SEM (FIML-SEM) and other types of multipath analysis usually require the endogenous variables in continuous responses. However, modified SEM can be used for various data responses (i.e., nominal and continuous data) of endogenous variables, so it can provide better results. The modified SEM can also solve the endogeneity issue of using the instrumental variables (IV) method as similar to the two- and three-stage least square method (2SLS and 3SLS) [
20]. Therefore, the modified SEM has more advantages compared to the conventional SEM method [
74] (detailed discussion of the modified SEM can be found in [
75,
76]). In this study, perceived usefulness is treated as continuous, and the frequency of taking ride-sourcing uses ordinal responses. The frequency of using ride-sourcing is better represented by ordinal responses than continuous responses since the observed values are not in a range from minus ∞ to positive ∞.
To apply different responses to different endogenous variables, the modified SEM is actually a combination of linear regression (LR) in the first stage (perceived usefulness) and ordinal regression (OR) in the second stage (ride-sourcing usage). Since it is a combination of two models, the global fit such as the root mean square error of approximation (RMSEA) cannot be estimated here (as also found in Dharmowijoyo et al. [
20,
64]) as in FIML-SEM and its variant. To apply the structural form, the modified SEM uses a similar approach to a 2-Stage Least Square (2SLS) and 3-Stage Least Square (3SLS) method. The creation of the perceived usefulness (
is like the creation of the first stage of 2SLS and 3SLS, also called the creation of an instrumental variable (IV), whereas the incorporation of the estimated perceived usefulness (
in the travel usage model is like the second step of 2SLS. As in 2SLS, the inclusion of
the estimated perceived usefulness using ride-sourcing tries to tackle endogeneity problems between the observed perceived usefulness (
Vi) and other variables (e.g., personal and travel characteristics, multi-tasking activities, and on-journey and before-journey advantages). The detailed equations are shown in Equations (1) and (2). As a limitation of this study, and similar to 2SLS, the first and the second stages were run separately; thus, the estimated error terms are assumed not to be correlated. In other words, different from 3SLS, which can be applied to correlate the third stage by correlating the error terms ε
1 and ε
2 of Equations (1) and (2), respectively, the modified SEM ignores the third stage. Therefore, the model sacrifices the simultaneous and the reciprocal effects. Myung [
77] defined this model of non-full information SEM using 2SLS as contrary to FIML-SEM and 3SLS. Since simultaneous effects are not expected to be a novelty of this study, the formation of journey and non-journey advantages, travel disadvantages, and the built environment were also not run simultaneously.
Using LR as the first stage, the equation to estimate the perceived usefulness is provided below:
where
Vi = perceived usefulness of the ride-sourcing by an individual
i. The right-hand side of Equation (1) consists of the following:
Pi = personal characteristics of individual
i,
Ti = travel characteristics of individual
i,
Bi = before-journey advantages using ride-sourcing of individual
i,
Oi = on-journey advantages using ride-sourcing of individual
i,
Di = travel disadvantage during travel by individual
i, and
Ei = built environment in individual
i’s residence.
Moreover, there are various scales of the predictors used in the models. Since most of the personal and travel characteristics, including multi-tasking activities during travel, are nominal variables, for incorporation into the regression analysis, we converted all of them into dummy variables. Dummy variables are used because this gives us opportunities to use a single regression equation to represent multiple categories [
78]. Latent variables such as
Bi,
Oi,
Di, and
Ei are treated as continuous variables that range from minus ∞ to positive ∞ as they are generated using explanatory factor analysis.
In the travel frequency model or the second-stage model, this study incorporates
(estimated perceived usefulness of the ride-sourcing of individual
i) from the perceived usefulness model applied into OR. Endogeneity problems were expected to be tackled by applying
instead of
Vi. The recursive structure between perceived usefulness and ride-sourcing usage was represented by applying
in the second-stage model. Since the dependent variable can be treated as ordinal, the likelihood of using ride-sourcing more or less (
y) was defined as shown in Equation (2), where the μ parameters represent thresholds to be estimated [
79].
With the OR model, the utility function can be written as follows:
Since the scale of the latent variable
y is arbitrary, it is common to assume that the logistic distribution for the residual is in its standard form, i.e., with mean 0 and variance μ2 = 3 (logit) [
79]. Additionally, for identification, one must either set one of the thresholds equal to zero or set the intercept to zero. In what follows, Raman and Hedeker [
80] suggested specifying the latter and estimating
j − 1 thresholds, with
j being the number of categories and
xi being the parameters in the utility function. The estimation of the parameters in the utility function uses Maximum Likelihood Estimation (MLE). With the full set of normalisation in place, the probabilities for the ordered choice can be written as follows [
79]:
Moreover, the stepwise method is used for both of the models, which is the step-by-step iterative construction of a regression model that involves the selection of independent variables to be used in a final model [
73]. Several variables that are not significant were still retained in the models due to their interactions with the goodness-of-fit of the models after a review during the stepwise process [
81].
6. Discussion and Conclusions
As expected, travellers who perceive ride-sourcing as useful positively correlate with a likelihood of high usage of the mode; having positive experiences of travel with a specific mode was also found in developed countries for different travel mode applications [
27,
32,
33,
34,
43,
85,
86]. Without perceiving the mode to be useful through perceiving high performances of before-journey components (e.g., high coverage, reliable applications and cashless payments, and low fares) and high performances of vehicles and drivers, people may not start to use the mode or may not repeat their use of the mode. Since the perceived usefulness shows the highest magnitude on travel usage and before-journey performance and the reliability of vehicles and drivers are the variables with the highest magnitude on perceived usefulness, reducing the before-journey performance, and the vehicle and driver performance will have a high impact on the perceived usefulness and ride-sourcing usage. Moreover, similar to an earlier study in Vietnam [
48], on-journey advantages, such as good quality of the vehicle (i.e., convenient and reliable) and the financial benefit (i.e., reduced travel cost), shape the appreciation of the services. On the other hand, perceiving reliable travel time and more productive time and other situational variables are not found to correlate with perceived usefulness but significantly correlate with whether users will use the mode frequently or not.
Even though travellers know that Bandung is a congested city [
84], perceiving a better travel time still correlates with a high magnitude of usage. With the high-level congestion in urban areas, the need for more efficient travel time trips has influenced people to use ride-sourcing [
9,
60]. Therefore, more advanced navigation systems for route selection and improving the drivers’ familiarity with their operation areas can be suggested as ways to reduce travel time and, in turn, increase usage. While it is proposed that ride-sourcing providers pool their drivers around locations with dense activity to reduce the waiting time, this pooling management might not be needed in good neighbourhoods in some suburban areas [
64]. There is a tendency for ride-sourcing to be used for short and medium distances in developing countries, as also found in other studies [
29,
59,
61], for reaching public amenities or shopping centres or public transport networks around the city centre.
This study confirms that multi-tasking is not a reason for ride-sourcing users to take the services more often. Those who are enjoying the view or reading/sending emails during the journey perceive negative experiences during the services, while those who are enjoying social interactions with the driver tend to be infrequent users.
By contrast with research in developed countries [
11,
31,
82,
83], educated generation X and older people perceive this service to be useful and take this mode more often. On the other hand, educated millennials may not feel this service to be useful but keep using this mode. This is presumably because generation X feels that this mode improves their mobility compared to what it was before the existence of this mode. Males take this mode more often, as in the UK [
82]. In developing countries, particularly Indonesia, males are workers [
30], so this mode seems to help male workers to improve their mobility. Moreover, motorcyclists and CBRS users are more loyal travellers than car and public transport users and MBRS, respectively. Therefore, CBRS users and motorcyclists who are part of the educated generation X and older can be offered a loyal user programme (e.g., as premium or titanium users with more benefits in using this service).
Since beginner users perceive negative experiences and take the mode infrequently, incentives can be provided to new users or those who have used the mode for less than 2 months in order to improve the perceived usefulness of the mode and increase the usage. Moreover, incentives such as discounts should be given to users who have a waiting time of more than 15 min; that can improve the perceived usefulness and the usage. However, given the issue of ride-sourcing competition with public transport, this incentive should be considered carefully, as ride-sourcing should not be a substitute for the demand for public transport [
9,
57]. Integrating financial incentives for ride-sourcing trips to public transport stations can be alternatives to support the public transport services.
During the COVID-19 pandemic, the demand for using this service tended to be reduced due to the travel restrictions, which particularly affected the demand for using public transport or quasi-public transport. However, it is reported that this service is also utilized for food delivery [
87]. But to avoid contact with crowds, some people adopting protective behaviour during the new normal period might choose this mode rather than public transport if they need to travel but have no private vehicle. Considering the limited public transport networks in developing countries such as Indonesia, due to limited public funding and the difficulties in changing road-oriented land use developments, this mode still has the possibility to act as quasi-public transport in improving the mobility of people in the new normal period. An emerging short travel mode might also be impacted by ride-sourcing, especially MBRS [
9,
10,
61]. In the future, the use of this service for food delivery and the likelihood of having short or long travel times using CBRS and MBRS can be investigated further. Therefore, understanding the effect of digitalization in transportation services will be relevant, particularly in developing countries such as Indonesia.