Forecasting and Trend Analysis Bus Transportation During COVID-19 in Bali Land Using Time Series Method

connectivity of Bali Island and the surrounding islands has increased after the COVID-19 pandemic subsided. It is hoped that it can be used as material for formulating public transportation strategies and policies, especially inter-provincial bus services.


Introduction
Bali is famous for its culture and tourism. Bali tourism can be accessed using available modes of transportation. Transportation serves as an important link between tourist destinations and locations outside Bali. The transportation industry is still feeling the impact of the COVID-19 epidemic. This is due to the additional need to utilize the Rapid-Test to travel to and from the island of Bali. As a result, the overall cost of the trip increases. This reduces public interest in coming to visit. The pandemic has had a major impact on transportation costs and shifts in travel requirements [1]. [2], [3].
COVID-19 has made a significant influence on global transportation. Australia's transportation industry suffers a severe financial collapse since public transportation utilization has dropped by 80% [4]. The general population's interest in using public transportation is dwindling [4]- [6] [7]. Public transportation is arranged to suit the community's demands for safe, pleasant, and inexpensive transportation [5], [8], [9]. This, however, was not met during the COVID-19 epidemic. Public transportation no longer gives the impression of safety and security. When taking public transportation, people are overwhelmed by their dread of getting the virus [5], [10], [11]. The transportation industry has a dual purpose as a transmission site and is impacted by COVID-19 [12]. On the one hand, public transportation must be protected, but on the other hand, public transit is a source of issues everywhere it grows [12] [13].
The income of the autobus suppliers reduces as the number of passengers declines.
Several autobus suppliers are innovating to expand the variety of services available in the transportation of goods packages. This has an impact on the longer trip time. Another tactic used by the Otobus Company is the consolidation of two travel routes to lower operational expenses. This affects the length of the route that must be taken, making travel time greater.
Furthermore, the points are not uniformly distributed, thus not all people's transportation demands can be met [14].
Following this, statistical studies that may explain variations in the usage of public transportation in Bali (particularly inter-provincial buses) before and after COVID-19 are required. Time series analysis can be utilized in statistical research [2], [3]. Data time series is a collection of data from a given phenomenon gathered over a defined time [15]. Using the time series analysis approach, we may learn about bus service variations between provinces. The period used for the analysis is from before to after the influence of COVID-19.
This article aims to utilize trend time series analysis to determine changes in the utilization of inter-provincial land transportation services. The study's findings are presented as trends in the use of inter-provincial buses [3]. Furthermore, the study's findings may be utilized to develop a policy plan for public transportation (Inter-Provincial Buses) and improve services

Research Data
This study is quantitative. is more consistent, making analysis easier [16]. Monthly departure data is derived from the total daily data. From this data, an analysis of the inter-provincial bus travel service departing from Mengwi Terminal Bali. It was carried out using the time series method of the number of trips, the number of departing destinations, the number of trips, and the average number of passengers, and forecasting using the four results of the time series analysis.

Instrument Test
A preliminary examination of the reliability and validity of the SPSS-aided data was performed before the statistical test. The validity test is used to determine the precision of the variables utilized in the study. A reliability test determines the dependability or consistency of study findings. If the significance value of the validity findings is less than 0.05 and the data is correlated, it is determined that the data is legitimate. Cronbach's Alpha Based on a Standardized test with a value greater than 0.7 was utilized for the reliability analysis [17].

Time Series Analysis
The next step is to test the Trend method for time series analysis. Time series analysis determines the development of one or several events and their relationship with or influence on other events [2]. The trend method was chosen based on the initial analysis of the data using scatter charts. Trend analysis shows the general direction of development (an upward or decreasing trend) [2]. This analysis determines the trend of inter-provincial bus services leaving

Minitab Software
Time series analysis was carried out using Minitab software. Minitab is one of the software programs created to perform statistical analysis. One of the statistical analyses can be done as a time series analysis. The software has a time series feature that can be used to find estimates of forecasting models and their forecasting results. Minitab software is considered capable of finding model estimates and time series forecasts [19], [20]. Four variables regarding bus services were analyzed using Minitab software. The items used are trend analysis with the four model types: linear, quadratic, exponential growth, and s-curve (pearl-reed logistics).

Instrument Test
Before time series analysis, validity and reliability were assessed. The SPSS program was used to conduct the analysis. Table 1 and Table 2 show the results of the Validity Test and Reliability Test performed with SPSS.   Table 1 shows that the significance value of all variables is below 0.05 and correlated. Therefore, the three variables are declared valid.  Table 2 shows that the value of Cronbach's Alpha Based on Standardized Items is more than 0.7, which is 0.898. As a result, it is said that all data is trustworthy.

3.2
Annual Data Analysis   Table 3 Population density data by city or district in Bali from 2018 to 2021 is explained in Table 4 [21].

Time-Series Analysis
Time series analysis was performed on monthly data from January 2018 to April 2022 (the data used are 52 datums), using the Minitab software and the Trend method. The trend approach model types employed were linear, quadratic, exponential growth, and S-Curve . The exponential trend model shows that forecasting data tend to fall closer to the x-axis (this graph is indicated by the asymptote = 0). The S-curve model shows that forecasting data tends to decrease to a certain value (this graph is marked by the asymptote = , for a positive number).   Service improvement refers to existing bus providers providing excellent service to customers. So, people choose bus providers as transportation service providers. It would be wise to study evidence-based policy responses to transport service delivery [22]. Research related to improving infrastructure, systems, and services provided to users of transportation services needs to be carried out. Various service innovations, ranging from competitive prices to easy access connected to the internet or computer [5], [23] have added to the attractiveness of this mode of transportation for consumers. For example, an intelligent information system lets passengers know the arrival time and availability of bus seats that go to their positions [24].

The Number of Bus Suppliers
Furthermore, it is critical to improving the safety factor. Perceived safety has a positive effect on overall satisfaction [14].    Table   6. Forecasting can be done because the MAPE value (9.48964) is in the range that can provide excellent forecasting results [18]. [18]  Forecasting results in Table 6  The tendency of the number of destination cities for interprovincial buses to increase at any time can be considered a pretty good opportunity. The increase in the number of destination cities indicates increasing connectivity between the island of Bali and the surrounding areas. Efforts need to improve inter-provincial bus services so that the community's public transportation needs are fulfilled. Service improvement can take the form of using an automated bus system or evaluating bus route management to shorten travel time. The development of public transport services can use three mobility principles: agility, integrated movement, and public-based partnerships [10]. In addition, tangibility, reliability, and responsiveness factors also need to be developed, which are service quality factors that significantly affect the satisfaction of public bus users [23].  Figure 3. This is because public transportation does not meet the needs of public transportation services [4], [18]. Furthermore, the model is used for forecasting until the end of 2022 (the 53rd to 60th data points are used) with Minitab software, as shown in the forecasting results in Table 7. Forecasting can be done because the MAPE value (of 39) is in the range that provides good forecasting results [18]. Forecasting results are in Table 7. Forecasting is carried out to find out the number of trips departing from Mengwi Terminal, Bali, until December 2022. However, considering the relatively large MAPE results, the forecasting results have not been able to provide a good (but reasonable) picture of future conditions.  Table 8. Forecasting can be done because the MAPE value (11.8102) is in the range of giving results for good fortune telling [18].

Conclusion
The results of a time series analysis with four variables show that the number of bus suppliers, the number of trips, and the average number of passengers tend to decrease over time.
The trend for the number of destination cities shows good results and continues to increase over time. Based on the forecasting results, the number of bus suppliers and trips has increased, although they have not yet matched January 2018. forecasting departures to increase constantly.
Thus, the connectivity of the island of Bali with the surrounding area is becoming increasingly good. The findings are expected to be used as material for formulating strategies and policies on public transportation, especially inter-provincial buses. The development of further research is still wide open, such as determining the connectivity between the island of Bali and the surrounding area or the factors that make an autobus provider more attractive to the public.

Acknowledgement
The authors acknowledge the opportunity and financial support provided to the director