• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.1
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• pp.44-57
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• 2020

A dedicated short-range communications (DSRC) traffic information system is a detection system for a section of road using communication between roadside equipment and on-board High-Pass units to collect road traffic information and provide reliable traffic information to drivers. The Ministry of Land, Infrastructure, and Transport announced that a DSRC system must be supported to pass the performance evaluation of an intelligent transportation system (ITS), and the performance evaluation for DSRC systems installed in expressways and national highways is started. Currently, DSRC traffic information systems are only managed for maintenance and functional-monitoring purposes, which means that detailed criteria for the operation of a DSRC traffic information system, such as communication range, the direction of the antenna, and the power of the radio wave, etc., need to be established. In this paper, the criteria of the performance evaluation of a DSRC traffic information system are presented for different road types and road environments. The proposed performance evaluation criteria included the communication range and communication power of roadside equipment. In addition, installation criteria, such as the direction of the antenna, and the height and angle of the installed system, are presented for different road types and road environments. The criteria presented were evaluated for DSRC roadside equipment and documented to improve system maintenance and quality control of the communication system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.36-56
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• 2022

Traffic accidents occur in Korea are calculated with the 「Automobile Accident Negligence Ratio Certification Standard」 prepared by the 'General Insurance Association of Korea' and the insurance company's agreement or judgment is made. However, disputes are frequently occurring in calculating the negligence ratio. Therefore, it is thought that a more effective response would be possible if accident type according to the standard could be quickly identified using traffic accident information prepared by police. Therefore, this study aims to develop a model that learns the accident information prepared by the police and classifies it to match the accident type in the standard. In particular, through data mining, keywords necessary to classify the accident types of the standard were extracted from the accident data of the police. Then, models were developed to derive the types of accidents by learning the extracted keywords through decision trees and random forest models.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.4
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• pp.60-67
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• 2010

Delay reduction of vehicles at the intersection is highly dependent on the signal operation method. Most previous traffic operations have focused on minimizing delay by adjust traffic offset. However, these methods have limitation in solving traffic problem if the volume reaches or exceeds the capacity. In this paper, it was analyzed that the effectiveness of various signal operation methods such as left-turn prohibition, and using protected mixed with permitted left turn using the traffic data from Daejeon city. In case of the left-turn prohibition of a intersection, the control delay reduced from 54.2 seconds to 22.7 seconds and especially, the delay of the southbound was drastically reduced. In addition, the delay was highly reduced from 27.0 seconds to 12.1 seconds when the operation system was changed to use protected mixed with permitted left turn.

• Journal of Korean Society of Transportation
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• v.31 no.6
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• pp.22-33
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• 2013

Currently average daily traffic using Hi-pass has increased over 3 times that of 2008 and more than half of highway traffic now uses High-pass. At this juncture, reassessment on the overall operation of Hi-pass is required to improve the safety aspect of toll booths and the flow of traffic. Although existing Hi-pass operation manual presents the methods of alignment, they do not reflect actual forms of vehicles and do not properly take the safety of toll booth and flow of the traffic into consideration. In order to compensate these problems, this study classifies highway tollbooths into two categories of mainline type and interchange type, and establishes the standard of lane alignment by traffic conflict analysis based on the types divided according to geometric structure or environment around the tollbooths. In addition, traffic flows around the tollbooths were reflected with the stage to arrange Hi-pass lanes according to the volume of traffic on the lanes for Hi-pass.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.59-67
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• 2002

2001년 경찰청 $\ulcorner$2001년판 교통사고통계$\lrcorner$ 자료에 의하면 사고피해의 정도를 나타내는 치사율에 있어서 중앙선침범사고가 과속사고와 함께 가장 높은 수치를 보이고 있으며, 대형 교통사고의 39.5%가 중앙선 침범에 의해 발생한 것으로 나타났다. 실제로 2000년 한 해 동안 총 사고건수 290,481건 중 중앙선 침범에 의해 18,931건 (6.52%)의 교통사고가 발생하여 사망자 1,472명, 부상자 35,046명으로 전체 교통사고 사망자의 14.38%, 부상자의 8.21%를 점하고 있는 것으로 나타났다. 이와 같이 전체 교통사고에서 중앙선침범사고가 차지하는 비중 이 높아지고 있어 중앙선침범사고를 줄이기 위한 대책의 일환으로 중앙분리대, 표지병, 시선 유도봉 등과 같은 중앙선침범 예방시설물을 설치하고 있으나, 해당 시설물에 대한 설치기준이 없는 실정이다. 이렇듯 중앙분리대 설치기준의 부재로 인해 중앙선침범사고 발생과 이에 따르는 경제적인 교통사고 비용손실, 그리고 중앙분리대의 과다설치로 인한 국가 재원의 낭비는 간과할 수 없는 문제점을 내포하고 있다. 이러한 점에 착안하여 기존에 지방부 2차로 도로의 직선부에 대한 중앙선침범사고 예측모델이 개발되었고 본 연구에서는 그 연장선상에서 지방부 2차로 도로의 곡선부에 대한 중앙선침범사고 예측모델에 대한 중앙선침범사고 예측모델의 개발을 통해 중앙선침범사고에 대한 사회적 비용을 산정하고, 현재 설치하여 운영중인 중앙선침범 예방시설물의 설치비용간의 비용-편익분석을 통해 얻어진 기준으로 중앙선침범 예방시설물 설치의 가부에 대한 보다 현실적이고 비용-효율적인 중앙선침범 예방시설물 설치기준을 제시함으로써 교통사고 비용손실을 최소화하고, 중앙분리대의 효율적 설치방안의 도입을 통한 경제적 이익창출을 도모하고자 한다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.3
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• pp.104-115
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• 2023

User-centered public transportation services such as DRT, Autonomous Transit etc. have been provied but current minimum level of service for public transportation has been evaluated by the operator because there is no data on user's accessibility to use public transportation. This study was performed GRID analysis using altteul transport card data including user's accessibility to use public transportation. The analysis result showed that user's accessibility to use public transportation was different within a same dong area. We proposed improving minimum level of service for public transportation considered by the user. The result of applying the proposed method showed that many area was changed to unsatisfied area for minimum level of service for public transportation

• Journal of Korean Society of Transportation
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• v.29 no.2
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• pp.47-58
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• 2011

Nowaday OECD countries actively introduce the performance audit to evaluate the performance of public policies. Motivated by the current trend in practice, this paper presents performance audit indices and methodology developed for evaluating the transportation investment projects and policies. The main contribution of this study would be twofold:1) key performance indices, 5Es + 4Cs rule, and methodology of performance audit are derived from foreign (GAO, NAO) and domestic (BAI) audit reports; 2) checklists (key issues and focuses) of performance audit are suggested as ranks. It is also suggested that further studies are needed to maintain the indices and the methodology to achieve sustainable performance of transportation projects and policies.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.1
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• pp.46-56
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• 2015

The purpose of this study is to find out the effectiveness of drivers' satisfaction over protected and permissive left-turn (PPLT) traffic signal operation. A structural equation model was established for analyzing the effectiveness of various drivers' factors (e.g., personal characteristics, driving attitude, expectation to PPLT, etc.) on the PPLT preference based on questionnaire survey. As a result, the analysis is satisfied with the critical values, such as Q value, RMR, GIF, AGIF, and NFI. The study reveals that PPLT preference increases in case of driver who is male with long social carrier related to transportation affaire and long driving experience without traffic accident involvement. Moreover, PPLT preference increases as the expectation of PPLT to improvement of traffic safety, traffic operation, and traffic environment increases. Therefore, it is recommended that the PPLT should be preferentially operated in urban area of less traffic accidents and the promotion of PPLT be actively conducted for positive effectiveness.

• Journal of Korean Society of Transportation
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• v.25 no.4
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• pp.79-87
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• 2007

The interchanges of urban freeways have many problems with traffic operation due to high off-ramp flows and frequent congestion at adjacent intersections. The flow exiting from off-ramps is affected by the operational status and traffic volume conditions of the nearest signalized intersection. As a result, off-ramp flow cannot exit and the queue backs up the freeway mainline when queues from the signalized intersection form up to the junction of the off-ramp and street. The spacing between an off-ramp and an adjacent intersection is likely to determine the traffic conditions at the adjacent intersection. However, the current design guidelines do not consider such a factor. This study is to develop a model calculating the spacing between off-ramps and adjacent intersections considering the signal, traffic, and road conditions. The variables affecting the model in this study are effective green time (g/C), volume-capacity ratio (v/c), the number of lanes, and off-ramp volume. Various scenarios are designed to represent the effects of the variables and the road networks are constructed using VISSIM, which is a common traffic micro-simulation software package. The queue length is derived from VISSIM and this length is considered as the recommended spacing between the off-ramp and the adjacent intersection. Through the simulation analysis, regression models are developed to calculate the queue length reflecting the various conditions such as signals, traffic, and road configurations. The developed model can be used to create road design guidelines to determine the location of off-ramps in the planning stage.

• Proceedings of the KOR-KST Conference
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• 1995.02a
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• pp.35-56
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• 1995

A methodology to the operation standards of the service performance of airport terminal fadlities using Perception-Response Model is discussed in this paper. The proposed approach has defined as the graphical presentation of the collective attitudes of a category of passengers towards the range of operational service at a facility of airport terminal. It adopts new concepts to establish service standards through special survey, that can achieve better interpretation of capadty and level of service at each facility. It is expressed in terms of perception of the passenger population of different amounts of the service measure and their response to the respective service conditions classified into distinct levels of satisfaction with service. The methodology can provide a practical service standards of airport terminals and may prove to be a practical and convenient technique to airport planners, designers, consultants, operators, and to airport managers.