A near-miss is an unplanned event that can precede events in which a loss or injury could occur. Therefore, it is an indicator leading to an accident. Near-miss analysis does not look at what happened but look into what could have happened. Serious conflicts are the result of a breakdown in the interaction between the road user, environment and vehicle, which leads to traffic accidents. As the similarity between accidents and serious conflicts is striking, accidents can basically be prevented by isolating and handling the conflicts potentials. The Swedish Traffic Conflict analysis of near-miss accidents is adopted in this study to improve the traffic safety of a channelized junction with U-turn at LentengAgung, Jakarta. The junction is a two-way junction with a wide median and an island. The location has been indicated as an accident-prone location with high conflict rates. A set of traffic video-recordings employing a number of surveyors at different points of observations were carried out on-site to obtain real near-miss accidents. Prior to the survey, surveyors practiced judging vehicles running speeds until they reached a certain maximum error of judgment. Evasive actions such as braking, swerving and accelerating were recorded, and actions were classified into serious and non-serious conflicts based on the time-to-accidents and speeds. The results of the analysis show that almost all of the total recorded conflicts fall in the category of serious conflicts. An improvement scheme of the junction with reduced potential traffic conflicts is proposed, which can be expected to lower the accidents occurrences.

Pedestrians are frequently perceived as one of the sources of traffic congestion due to their illegal occupancy of the roadway. The goal of this study is to examine this issue by investigating the feasibility of pedestrian facilities and the effectiveness of utilizing a pedestrian bridge at a certain congested area: the north-bound traffic in Jalan Lenteng Agung, Jakarta. The feasibility of a facility is represented by an indicator of the Level of Service (LOS), i.e. the space occupied by one pedestrian, and is supported by an assessment from the pedestrian's point of view, using a questionnaire covering various aspects of the issue. The assessment of its geometric feasibility is also carried out, using the design specifications issued by the Directorate General of Bina Marga (1990) to strengthen the analysis. Meanwhile, the effectiveness of using a pedestrian bridge is represented by the ratio of pedestrian bridge users to the total number of people crossing the street. Data collection related to pedestrian flow is carried out using web cameras. The analysis shows that the LOS of all the segments of the pedestrian facilities ranges from LOS A to LOS C, in which LOS C represents the pedestrian bridge. LOS measures, supported by the geometric feasibility assessment results, signify that the facilities are not yet feasible; the speed of pedestrian flow needs to be increased using geometric improvement and the elimination of all disturbances throughout the facilities. Meanwhile, the effectiveness of using the pedestrian bridge is only 50.26% (meaning it is "quite useful"); the remaining percentage of pedestrians cross the road by navigating through the road traffic. The questionnaire results show that people are indeed aware of the importance of the safety issues related to bridge usage; however, they are reluctant to use it due to the physical barriers. The improvement generated from the analysis may help increase bridge use and its LOS, and eventually reduce the disturbance of vehicle flow.

A median is required for a two-way road to separate the opposite traffic and prevent head-on collisions. In road capacity calculation, the median factor contributes in terms of its existence regardless of the difference in median types. Road capacity is determined by a number of geometric factors such as road types, width of carriageway, shoulder/curb characteristics, and the presence/absence of medians, etc. The contributions of these factors are represented by the coefficients in the capacity calculations. Despite the different types of medians, the Indonesian Highway Capacity Manual (IHCM) does not adopt different coefficients to accommodate the effects in the capacity. The aim of this study is to obtain an adjustment factor for road capacity calculation based on median types. The method of this study adopts video recordings of real traffic moving along three different types of medians: raised medians, fenced medians, and line medians. As it is assumed that the effects of different median types are expressed in the vehicles' safety distances from medians, the capacity of the road will also vary by types of medians. The adjustment coefficients for roads with raised medians, fenced medians, and line medians obtained are: 0.79, 0.78, and 0.81, respectively. The results of this study confirm that in addition to the presence of the medians, the types should essentially be considered in calculating the road capacity. The result of this study will contribute to the enrichment of the road capacity calculation in the IHCM.