Enrichment: Journal of Multidisciplinary Research and Development

ABSTRACT


INTRODUCTION
Jakarta, the capital city of Indonesia, is facing severe transportation problems due to its growing population and increasing number of vehicles on the road.Congestion, air pollution, and long travel times are major issues that affect the daily lives of citizens and hinder the city's economic growth.To address these issues, the Indonesian government has initiated several transportation projects, including the development of the Light Rapid Transport (LRT) system.Based on the urgency above and relying on Presidential Regulation number 99 of 2015 concerning the Acceleration of Public Transportation Implementation in DKI Jakarta Province, then the DKI Jakarta government appointed PT-JPo and PT-PJ to build the Jakarta LRT.Furthermore, the Jakarta LRT began work on June 22, 2016 and as the implementing contractor at that time was PT-WK (Negara, 2007) (Nomor,72 C.E.).
In the initial stage, two lines are planned, namely the north line and the south line.The northern line has been able to operate for public services since December 1, 2019, and the company appointed in operation is PT-LRT-J.The line has a rail length of 5.8 km, starting from Pengangsaan Dua Station (Kelapa Gading area) to Velodrome Station (Pulo Gadung area) (Pratama et al., 2020).It has been almost three years since the northern line has been in operation, the fact now also shows that during rush hour there are queues of crowded users.Preliminary studies through several respondents also showed that there was dissatisfaction with LRT users regarding the waiting period on the LRT, so studies related to the study of the operating system of the north line Jakarta LRT are urgent to be reviewed (Ramadianti & Widyaningsih, 2020) (Rahayu Putri, 2023).
Studies related to this topic were previously conducted by (TSURAYYA ZAHIRAH, 2011).Referring to the user satisfaction survey, (TSURAYYA ZAHIRAH, 2011) conducted an analysis related to the existing operating system by shortening the existing headway of the north line Jakarta LRT.However, the study has not confirmed how effective the proposed headway is for the northern line Jakarta LRT operating system, and what risks are likely to occur and how to mitigate these risks.Referring to this gap, this study aims to determine the effective headway of the north line Jakarta LRT, as well as identify potential risks that may occur and design risk mitigation due to changes in the north line Jakarta LRT operating system with a new headway.

METHOD
In this study, two research approaches were used, both quantitative and qualitative approaches.This research was carried out in the following stages: 1. Study of Passenger Waiting Time Expectations This stage aims to determine the expected waiting time from passengers within the research subject.Data was collected by the questionnaire method which was carried out by the online method.A set of questionnaires in the form of a google form link was submitted to respondents consisting of several questions related to demographics and main questions.The main question aims to identify the most expected waiting times of north line Jakarta LRT passengers.Based on the Slovin formula, the number of respondents used in this study was 100 LRT users.Slovin formula.

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The results of filling out the questionnaire by respondents were then processed using statistical methods to obtain a description regarding the waiting time expected by north line Jakarta LRT passengers during rush hours.

Analysis of Existing Operating System
Analysis of the existing operating system is carried out to obtain an overview of the existing operating conditions of the north line LRT Jakarta, as well as being used as a basis for proposing changes to operating parameters to achieve optimization of the operating system.The main goal at this stage is to find out the parameters of the existing operating system on the the north line Jakarta LRT.The data used are secondary data obtained from online official sources and the results of literature studies, including documentation studies.The formula is quoted from (Supriadi, 2008a)  In this stage, we conduct an operating system analysis focused on the anticipated waiting time for LRT users.Similar to the previous stage, we rely on secondary data from the initial studies, online official sources, and literature including documentation studies.The formula used for this analysis is derived from (Supriadi, 2008b) and (TSURAYYA ZAHIRAH, 2011), which help determine acceleration and deceleration, braking distance, circulation time, and the required number of LRT fleets, as in the earlier phase.

Risk Analisys
The main objective of this stage is to identify primary risks related to changes in the operating system of the north line of Jakarta LRT due to headway modifications and develop effective mitigation strategies.The chosen research approach is interviews.Participants include 5 expert practitioners with at least 10 years of LRT service experience and academic practitioners with similar experience.Their selection is based on extensive knowledge to provide valuable insights into risks linked to the north line's operating system changes (Salsabilla et al., 2023).
Data was gathered through interviews using open-ended questions to encourage detailed responses.The three main questions covered the feasibility of proposed changes, primary risks, and mitigation efforts.Preparations were made for a smooth process, including scheduling, an appropriate interview environment, and obtaining consent and permissions.Data analysis involved qualitative techniques, noting detailed responses from audio or video recordings.Key risks and risk response plans were identified.To ensure reliability and validity, responses were cross-referenced, and multiple researchers assessed data consistency.
Expected results include identifying key risks and developing risk response plans based on insights from expert practitioners and academics, contributing to effective risk management for the north line of Jakarta LRT. Figure 1 below is a methodology diagram in this study (Wibowo, 2022).

RESULTS AND DISCUSSION
The following description presents the results and discussion related to this research.

Waiting Time Expectations
Following are the results of collecting data on respondents using a questionnaire.Data was obtained on LRT operational days (Monday-Friday) during peak hours 05.30AM -08.30AM and 16.00 PM -19.00 PM, also on non-busy days (Saturday and Sunday).

Existing Operating System
An analysis of the existing operating system was conducted to depict the operational conditions of Jakarta LRT and assess the need for optimization through the addition of LRT train operations.Following the calculations using the equations above, here are the results of the analysis of the existing operating system pattern.Based on the speed formula, the existing speed is 25.04 km/hour.Referring to the farthest distance of the stake, which is 950 meters, a minimum headway of 6 minutes is obtained.Table 3 below shows some of the existing operating parameters consisting of minimum automatic block headway capability and track capacity.

Headway Capability and Track Capacity
The existing headway values consist of an equipment replacement time of 3 minutes and a facility cleaning time of 4 minutes, then the waiting time for the Jakarta LRT north line (WTT) terminal is shown in Table 4

Proposed Operation System
Following are the results of the analysis in the form of parameters of the operating system pattern based on the proposed headway: a. Travel time Referring to the technical specifications of the facility, with a maximum operational speed of 80 km/h, and with an acceleration and deceleration of 1.0 m/s2, the following description is the proposed graphical speed calculation with a maximum speed of 90%, as well as calculation of acceleration and deceleration.
v=80×90%=72 km⁄h Based on the calculation of the speed equation, the acceleration and deceleration for 20 seconds of the train are obtained as follows: Based on the service parameters above, the braking distance is 200 meters long, so the travel time can be obtained according to Table 6 below.
Table 6.Travel time The results of calculations using the speed equation with a travel time of 8.7 minutes obtained an operational speed of 37.41 km/hour.b.Terminal waiting time The proposed terminal waiting time can be reduced to 3 minutes, assuming that cleaning the internal facilities of the train can be done while the train is running, so there is no special time for cleaning when the train is stationary.Table 7 shows the terminal waiting time (WTT) for the proposed operating pattern system.Table 7.The proposed headways consist of peak and non-peak periods.Also taking into account the operating time period, the number of fleets, and the number of trips.Table 8 below is the proposed headway which is calculated based on the equation for the number of fleets.Table 8 also shows that the proposed headway (5 minutes) during peak hours is still above the minimum headway threshold (3 minutes: according to Table 7).4. Risk and Mitigation Table 9 below is the result of an in-depth interview in identifying risks and their mitigation plans due to changes in the pattern of the operating system on the north line of Jakarta LRT -Indonesia.

CONCLUSION
Based on the results of the analysis and discussion in this study, the conclusions are as follows: There are 40% of north line Jakarta LRT users want the waiting time at peak time at 05.30 -08.30WIB for 5 minutes, and 42% want the peak time at 16.00 -19.00 WIB to be 5 minutes.Based on the results of the analysis of the proposed pattern of operating system the north line Jakarta LRT by using a headway during peak hours for 5 minutes and non-peak hours for 10 minutes, this shows that it still meets operational feasibility.As a result of discussions with expert practitioners, 14 potential risks were identified as a result of changes in the proposed operating pattern.The results of discussions with expert practitioners also resulted in a set of action plans needed to mitigate these potential risks.Future studies can be continued by identifying the factors that affect passenger satisfaction and propose steps to improve the overall user experience.
and (TSURAYYA ZAHIRAH, 2011) and is used to obtain the speed, headway, track capacity, circulation time (WPS), and number of LRT fleets required (Pasila et al., 2019).The formula used is as follows.departure+WTT arrival e. Number of LRT fleets Number of fleets = WPS/(H×0.85)×the number of carriages in one LRT fleet 3. Analysis of Proposed Operation System time of train The results of calculations using the WPS equation obtained a train circulation time of 23.4 minutes.d.Proposed headway and number of fleets

Table 1 .
Jakarta LRT passenger survey results Table 2 below shows travel time existing.Table 2. Travel time -Existing

Table 8 .
Headway and other proposed operating system parameters

Table 9 .
Resume of risks and mitigation plans More routine periodic checking of signaling systems Enrichment: Journal of MultidisciplinaryResearch and Development, 1(6), 2023