Correlation the Urban Mobility and COVID-19 Case in Yogyakarta City

COVID-19 is an outbreak that spreads mainly due to human interaction. Transmission is greater when there is a potential crowd. So, the main policy in dealing with the spread of COVID-19 is to limit interactions. Interaction restrictions are carried out in various ways from social distancing to mobility restrictions. Mobility restriction means reducing the movement of the population for various purposes of movement. The less movement the number of transmissions of COVID-19 cases will also decrease. However, in various studies it turns out that this is not always the case. Reducing movement does not necessarily reduce the number of positive cases. Therefore, the purpose of this study is to find the correlation between population mobility and the spreading of COVID-19 cases in Yogyakarta City. Yogyakarta is one of the cities in Indonesia that is the epicentre of COVID-19. This research uses descriptive quantitative method and correlation analysis technique. The population mobility was obtained from primary data in the form of questionnaires, while COVID-19 cases were obtained from secondary data which provided by the Municipality of Yogyakarta City. The results of the analysis show that there is no correlation between the transportation mode choice and frequency of travel, and COVID-19 spreading. However, the travel time has a positive and significant correlation with the spreading of COVID-19.


Introduction
For about two years, almost the entire world has been dealing with COVID-19 cases.Coronavirus Disease-19 or COVID-19 is an infectious disease caused by a newly discovered type of coronavirus.WHO or World Health Organization names the new virus as Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) which can cause respiratory system disorders [1].The first case of COVID-19 occurred in Wuhan City, China in late December 2019 and was transmitted between humans very quickly and eventually spread to dozens of countries including Indonesia in just a few months.The spread of COVID-19 in Indonesia first occurred since the COVID-19 case was announced by the Indonesian Government on March 2, 2020 and for the first time there were cases of death due to this virus in Indonesia on March 11, 2020.
The keyword for the spread of COVID-19 is interaction, so the main handling effort is to reduce interactions between humans [2].Reducing interactions between humans is realized in various policies IOP Publishing doi:10.1088/1755-1315/1353/1/012012 2 including social distancing [3].Social distancing is mainly done by maintaining a safe distance between humans.Interaction is still carried out but with certain restrictions and health protocols.Meanwhile, apart from social distancing, there is also an isolation policy.Isolation is carried out in the most emergency conditions where the population is prohibited from interacting with each other at all [4].
Isolation can be done for each individual or occur in an area or city depending on the policy.The policy of isolating an area or city uses the term lockdown while in Indonesia it uses several terms such as Large-Scale Social Restrictions (PSBB) and the Enforcement of Restrictions on Community Activities (PPKM).The government issued a legal basis to accelerate the handling of the coronavirus, one of which is Large-Scale Social Restrictions which is regulated by Government Regulation no.21 of 2020.Large-Scale Social Restrictions are regulations issued by the government, especially the Ministry of Health of Republic of Indonesia in order to accelerate the handling of the COVID-19 pandemic that is currently endemic.Thus, the implementation of Large-Scale Social Restrictions and the Enforcement of Restrictions on Community Activities changed social economic condition of society in Indonesia [5].
In Indonesia, lockdown policies, including Large-Scale Social Restrictions and the Enforcement of Restrictions on Community Activities are carried out through various policies such as eliminating and prohibiting various activities that allow crowds to occur.Work from Home (WFH) is implemented in various fields, namely education and offices, both government and private.The service trade sector is also restricted by reducing activities in trade and shopping centres.In addition, the government restricts mobility and the use of transportation facilities.People are also switching to using their private vehicles with the intention of avoiding COVID-19 transmission.The sharp decline in demand for public transportation is due to the new distancing behaviour and fear of contracting in public transportation [6] [7] [8].
The Indonesian government has implemented a policy of limiting population mobility by implementing various schemes.The restrictions on population mobility are applied to all modes of transportation, private and public, by land, sea and air.The restrictions on private modes of transportation, generally land, are carried out by guarding various roads that become border points between administrative regions.Private vehicles that reach the border area are forced to return to the area of origin.For public transportation modes, efforts are made to stop or reduce fleet departure schedules [9].
People use more of their private vehicles because they are afraid to use public transportation.This naturally leads to a shift in the choice of transportation modes in urban mobility [10].As a consequence of the global spread of the coronavirus, daily mobility habits have changed significantly around the world.People avoid using public transportation such as buses, trains and shared car transport worldwide.Private transportation and bicycles are the preferred modes of transportation [11] [12].
The policy of limiting mobility and the use of transportation means has a direct impact on the decline in population mobility.Residents perform mobility only for very urgent activities.COVID-19 disease is more influenced by population mobility factors, especially mobility within the city [2].Limiting population mobility is one of the efforts to control and control the spread of infectious diseases [13].Past events have proven that population mobility is strongly associated with the spread of infectious diseases [14].
However, reducing population mobility is not necessarily effective in reducing positive COVID-19 cases.There are various contexts and cases that make reducing population mobility not always positively correlated with reducing COVID-19 cases.Low mobility was found to be positively correlated with a spike in daily COVID-19 cases in short spans of time or holidays, which can be said that the presence of community mobility does not directly correlate to an increase in cases.However, the presence of community mobility causes local transmission which then forms dispersal clusters which then spread in family and housing clusters due to residents preferring to stay at home during short periods or holidays [15].
Therefore, this study aims to analyse the correlation between urban population mobility and COVID-19 cases in Yogyakarta City.Yogyakarta City is one of the epicentres of COVID-19 cases on the island of Java.Yogyakarta is one of the cities in Java that have high density.Numerous earlier researches have demonstrated that density influences the spread of COVID-19 because denser populations have higher interaction potential [16].Understanding this correlation has a very important role because local policy makers can use the urban mobility, a fundamental activity carried out by the community, as an instrument in controlling the spread of COVID-19.By observing the correlation between urban mobility and the trend of COVID-19 cases, the policy makers can determine whether or not urban mobility needs to be restricted, how far the restrictions should be, how large the restricted area should be, and how long the restrictions should be in place.

Method
This research uses the mobility data of community and the level of spread of COVID-19 in Yogyakarta City.The mobility of community relates to several variables including the travel mode choice being used by the community, the travel time demand, and the frequency of travel by community.The travel mode choice is an important element in transportation planning and policy-making in order to understand and forecast travel demands [17].One of transport facility characteristics is travel time, beside of monetary cost, reliability, availability [18].In the context of COVID-19 spreading, the travel time of mobility relates to the risk of human interaction in the public spaces.Meanwhile the frequency of travel relating also to the purpose of trips influences also the urban mobility during the pandemic era.The change of trip characteristics especially trip frequency occurs in a post-lockdown scenario [19].The descriptive quantitative method and the correlation analysis techniques are utilized for this research.This research analysis technique is used for assessing the correlation between urban mobility and the level of spread of COVID-19 in Yogyakarta City.The research data consisted of primary data derived from a survey using a questionnaire with 452 and secondary data.Primary data came from a survey using a questionnaire to the residents of Yogyakarta City.While secondary data can be obtained from the Health Office of Yogyakarta City.So by comparing the fact of the increasing spread of COVID-19 with the fact of increasing urban mobility, it can be seen whether there is a positive or negative correlation between those factors.In identifying the distribution of COVID-19 in the city of Yogyakarta, researchers used a categorization analysis technique [20].In our research, the categorization of the level of COVID-19 spreading is divided into 5 (five) classes as follows.

Classification Formula
Very Low X < M -1,5SD Very High M + 1,5SD < X Note: case number or score (X), mean of all the numbers (M), standard deviation (SD) Source: Azwar, 2012

Identification of the Number of COVID-19 Confirmed Cases in Yogyakarta City
The  Based on Figure 1, Rejowinangun Sub-district has the highest number of cases with 1.286 cases and the lowest COVID-19 confirmation cases is in Suryodiningratan Sub-district with 336 cases.Based on Figure 2, the category of sub-districts with high cases with a range of 1.235 -1.302 cases are located in 2 (two) sub-districts, namely Baciro Sub-district and Rejowinangun Sub-district.The category of medium-case sub-districts with a range of cases between 998 -1.235 cases is located in 6 sub-districts or 13% of the total number of sub-districts in Yogyakarta City.The category of sub-districts with low cases with a range of 762 -998 cases occurred in 10 sub-districts or 22% of all sub-districts in Yogyakarta City.The category of sub-districts with very low COVID-19 cases with a range of cases less than 762 cases are located in 27 sub-districts or 60% of the total sub-districts in Yogyakarta City.  Figure 2 describes that the sub-districts with a very low number of COVID-19 cases are dominant in the central part of the city, west of the city, and north of the city.Meanwhile, sub-districts with high COVID-19 cases are located in the east and north of the city as shown in the map above.Based on the results of data processing and observations, data related to the number of positive COVID-19 communities in each sub-district in Yogyakarta City will be categorized using 5 (five) categories and then interpreted into zones with very high distribution, zones with high distribution, zones with moderate distribution, zones with low distribution, and zones with very low distribution.It shows the calculation and determination of categorization for COVID-19 confirmation cases in Table 3.It can be seen that very low categorization has less than 762 cases, low categorization has more than 762 cases but not more than 998 cases, medium categorization has more than 998 cases but not more than 1.235 cases, high categorization has more than 1.235 cases but not more than 1.302 cases, and very high categorization has more than 1.302 cases.The following is a tabulation of COVID-19 confirmation cases for each sub-district in Yogyakarta City.This study also conducted interviews with people who had been COVID-19 survivors in each sub-district with a total sample size of 452 people.The interviews conducted took at least 4 (four) respondents in each sub-district.The following are details of the number of respondents in 45 subdistricts in Yogyakarta City.

The Characteristics of Residents Mobility in Yogyakarta City
In general, the COVID-19 pandemic has changed the characteristics of residents' mobility of Yogyakarta City, who used to travel frequently and now prefer to reduce mobility.One of the factors influencing the change of trips characteristics is the restrictions on activities that require residents to stay at home during the pandemic.However, there are still residents who did not reduce mobility due to work demands that require presence at the workplace.Based on the spatial observations in Figure 5, almost all sub-districts in Yogyakarta City have residents who reduce their mobilities or travel activities.However, there are still several sub-districts where a high number of residents did not reduce their mobility.Meanwhile, only in a few sub-districts where the residents sometimes reduce their travel activities.In addition, Figure 7 demonstrates that the online transportation mode is not the main choice of transportation mode.However, it is the preferred mode of transportation which is dominated by the selection of online transportation modes for two-wheeled motorbikes.

Figure 7. Number of Online Transportation Mode Voters
Based on Figure 8, the use of private vehicles is mostly dominated by the use of motorcycle twowheeled vehicles.The two-wheeled vehicles are most preferable vehicles among people because of their high mobility capabilities.The motorcycles can reach every corner of the city easily, and are relatively cheaper.The cars, despite their advantages, have limited mobility, especially in areas prone to traffic jams.Meanwhile, there are still very few bicycle users due to the relatively hot and humid weather, making cycling less comfortable.In addition, the bicycle support facilities are also lacking.Figure 11 shows that the frequency of travel.The residents' mobility is dominated by the frequent trips occurring due to work demands and interests that require residents to leave the house.The frequency of travel is also sometimes done, which occurs due to urgent interests that need to be done outside the home.Meanwhile, the rarely travel has the smallest number.

Figure 11. Number of Travel Frequency
Based on the discussion above, it can be concluded that the residents' mobility characteristics in Yogyakarta City during the COVID-19 pandemic have changed due to the imposition of Restrictions on Community Activities (PPKM) and Work from Home (WFH) so that the residents reduced their mobilities or travels.This situation explains that there is a correlation between activity restrictions and reduced mobility and there is a correlation between doing activities at home such as WFH with reduced COVID-19 cases.
The mobility characteristics of residents in Yogyakarta City prefer to use private transportation such as two-wheeled and four-wheeled vehicles rather than using government public transportation.However, online transportation is still an alternative choice for residents to carry out mobility.Travel time is dominated by trips that take less than fifteen minutes (15 minutes).In general, there is no change in the purpose of travel both before and after COVID-19 because the average trip destination is still the same as before COVID-19.Meanwhile, the dominance of the frequency of trips made by residents of Yogyakarta City is still frequent.This is related to the variables of reduced mobility and variables of travel destinations.Based on the data and the interview, although the mobility of the population is reduced, the population has the same or fixed travel destination, both before and after the existence of COVID-19.So, even though they have reduced mobility to other places, residents in Yogyakarta City still often carry out mobility with fixed travel destinations such as for work activities and other interests.

Significant Correlation between the Urban Mobility and COVID-19 Case in Yogyakarta City
After conducting some data identification related to population mobility associated with the high number of COVID-19 survivors in each sub-district, the next step is to analyze to determine the correlation between community mobility and the number of increases in COVID-19 cases.The variables chosen to see the correlation are the variables of transportation mode, time, and frequency.Based on the results of the analysis, there is no correlation between the number of COVID-19 survivors and the mode of transportation as indicated by a p-value of .115.This condition shows that the use of transportation modes in Yogyakarta City is very weak in relation to the number of confirmed COVID-19 survivors.This is unique because transportation modes should have great potential to become a place of virus transmission due to the potential crowd in the transportation mode.However, the situation is the opposite due to the policy of reducing community activities.This policy has drastically reduced the use of public transportation modes and most of the population travels using private transportation [11] [12].
In addition, the frequency of travel shows that there is no correlation between the number of COVID-19 survivors and the mode of transportation marked with a p-value of .088.This means that someone who travels regularly during a pandemic is not necessarily more at risk than someone who rarely travels during a pandemic.
Of the three variables above, the travel time variable shows a correlation with the increase in COVID-19 cases in Yogyakarta City.This indicates a strong correlation between people who take too long to do activities outside that can cause transmission of the virus.The longer people are outside, the more potential there is because the virus can last several hours in the air and be carried by the wind [21].

Conclusion
Based on the research that has been conducted, it is concluded that travel time has a positive and significant correlation with the high number of COVID-19 cases in Yogyakarta City.This means that the duration of travel taken by the community when outside the home can lead to an increase in the number of COVID-19 cases.This finding strengthens several previous researches that mentioned one of the factors influencing the spreading of COVID-19 is the duration of human interaction.The long travel time increases the probability of human interaction in the transportation modes or urban streets.The other finding is the mode of transportation and the frequency of travel do not describe a correlation with the increase in COVID-19 cases.The analysis results indicated the correlation between the spreading of COVID-19 and various transportation modes could not be explained.The implementation of health protocol in the use of transportation modes has the risk reduction probability of COVID-19 spreading.The strong implementation of health protocol in public transportation tends to reduce the COVID-19 spreading.
On the other side, the COVID-19 pandemic has made people's mobility very limited.Apart from the policies implemented by the Yogyakarta City Government, public awareness of the virus and its safety also makes people reduce activities outside the home, especially in public places such as shopping centers, supermarkets, or minimarkets.Even though generally the mobility of the community was decreasing in the pandemic era, the purpose of trips remains the same condition, and the frequency of travel is still frequent.This situation reinforces that those factors do not correlate with the spread of COVID-19.However, this research only used a single case of Yogyakarta City.For the next research, these research findings could be compared to the other cities in particular the Indonesian cities having the same size of urbanization degree, and the same regulation of community activities restrictions enforcement during the pandemic of COVID-19.
Article 1 paragraph (1) of the Regulation of the Minister of Transportation of the Republic of Indonesia No. 18 of 2020 Transportation Control in the Context of Preventing the Spread of Coronavirus Disease 2019 (COVID-19) states that, transportation control in the Context of Preventing the Spread of Coronavirus Disease 2019 (COVID-19) is control in the form of restrictions on transportation modes.
No different purpose of trips Different purpose of trips Special Region of Yogyakarta can represent the dynamics of the COVID-19 transmission rate associated with community mobility.With the Decree of the Governor of Yogyakarta No. 65/KEP/2020 on the Determination of Disaster Emergency Response Status issued on March 20, 2020, the Government of the Special Region of Yogyakarta (DIY) established a disaster emergency response status as an effort to stop the spread of COVID-19.Then on March 4, 2022, Yogyakarta City entered into Community Activities Restriction Enforcement with level 4 (four).This is in line with the Extension of the Implementation of Level 4 Restrictions on Community Activities which is by DIY Governor Instruction No. 9 of 2022.

Figure 1 .
Figure 1.Number of COVID-19 Cases each Sub-district in Yogyakarta City Source: Yogyakarta City Health Service, February 2022

Figure 4 .Figure 5 .
Figure 4. Number of the Mobility Reduction by the Residents each Sub-districts

Figure 6 .
Figure 6.Number of Transportation Mode Choice

Figure 8 .
Figure 8. Number of Private Transportation Use

Figure 10 .
Figure 10.Duration of Travel Time

Table 3 .
Categorization of COVID-19 Confirmation Cases in Yogyakarta City

Table 4 .
Tabulation of COVID-19 Confirmation Cases for Each Sub-district in Yogyakarta City

Table 5 .
Correlation between The Urban Mobility and COVID-19 Case in Yogyakarta