• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.41-47
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• 2005

Traffic data such as traffic volume, speed, and vehicle Class are very important basic data for the plan and design of highway. Based on traffic data, the future service level of a specific highway and geometry of newly constructed or expended road is predicted and determined. The Ministry of Construction & Transportation has simultaneously surveyed coverage count and permanent count at highways since 1985. Traffic volume survey sections were determined at jointed nodes of highways and jointed nodes of highways and other roads such as freeway and local highway. Volume survey was performed at these sections. The premise to decide these sections is assumed that links between jointed nodes of main highways exhibit similar traffic characteristics. Recently, due to the change of highway geometries such as construction of detour road and installations of traffic facilities such as installation of media, traffic characteristics of the existing traffic volume survey sections was changed. To reflect these changes, traffic characteristics at homogeneous road sections was widely evaluated and analyzed. Using Genetic Algorithms, a model was developed for the evaluation of traffic characteristics at homogeneous road sections. Traffic volume survey sections were then determined through the application of the developed model for current traffic system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.3D
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• pp.205-212
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• 2012

The national highway traffic counts system consists of short duration counts and continuous counts. Unlike continuous counts, short duration counts are performed by collection of a few days period and thus, the magnitude of deviation of collected data from AADT varies depending upon when data collection takes place. Therefore, this study was done to find out the best months and days of data collection of each highway classification in order to enhance the accuracy of AADT estimation. Continuous counts, another type of the national traffic counts system, are performed by collection of 365-day period using a permanent traffic counter. Therefore, it is necessary to keep the number of days for which the counter malfunctions to a minimum in order to enhance the accuracy of data. However, from time to time the permanent traffic counter malfunctions due to various causes and thus, cannot collect data. Therefore, this study was done to find out whether the age of counter, the ratio of heavy vehicle volume to total traffic volume, etc. could be the direct causes of counter's malfunction based on the number of maintenance for a certain time period.

• Journal of Korean Society of Transportation
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• v.26 no.1
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• pp.203-213
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• 2008

U-Turn offers convenience to drivers. U-Turn increases efficiency of traffic flow. But Standard of U-Turn is not clear. It caused many problems of traffic flow and traffic safety. This study estimate length between U-Turn location with front intersection based on stopping sight distance and left-turn vehicle's queue length. Variables are used traffic volume and operation speed. This study Analysis of U-Turn vehicle's behaviors and classification of conflict form by investigation. U-Turn length estimating based on relationship analysis between conflict with U-Turn length. Variables are used lane changing angles and operation speed. This study estimates length between U-Turn location with back intersection based on gap acceptance theory. Variables are used traffic volume, operation speed and lane changing angles. So, U-Turn location and length estimated considering traffic flow and traffic safety.

• Journal of the Korean Society of Safety
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• v.32 no.6
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• pp.131-136
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• 2017

This study deals with the small-size roundabout accidents. The purpose of this study is to analyze the characteristics of small-size roundabout accidents from developing various types of accident models, and to discuss the improvement countermeasures by vehicle type. The geometric characteristics of 36 roundabouts are surveyed, and the traffic accident data from 2008 to 2014 are collected and classified as those of car, truck and motor cycle. In this study, dependent variable is the number of accident and independent variables are such 15 variables as geometry and traffic volume. The main results are as follows. First, the null hypotheses that the size of roundabout and type of vehicle are not related to traffic accident are rejected. Second, 8 count data models which are all statistically significant are developed. Third, the number of circulatory roadway lane and sidewalk are selected as common variables of roundabout size. Finally, the number of entry and circulatory roadway lane are selected as common variables of vehicle type.

• Journal of Korean Society of Transportation
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• v.29 no.2
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• pp.7-14
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• 2011

This paper discusses operational technique and effectiveness of Variable Speed Limits system that is implemented to control the traffic-flow on the Naebu Expressway. As the first step of the analysis, traffic data collected from vehicle detectors are corrected and smoothed. Applying a pattern analysis technique to the traffic data, the weekday traffic is classified into four different groups, and median of each group is calculated. Using three state variables, i.e., diverted traffic volume, average density and average speed, the conditions of roadway segments are determined. Computational outputs resulted from the application of the proposed model to the scenarios show that implementation of Variable Speed Limits system improved both safety and efficiency of the expressway. For the operational strategy, this paper also presents the change rate of the speed limit, and the effective duration of the speed limit according to the entering traffic volume.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.2
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• pp.28-38
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• 2001

Traffic information can be broadly categorized into point information and spatial information. Point information can be obtained by chocking only the presence of vehicles at prespecified points(small area), whereas spatial information can be obtained by monitoring large area of traffic scene. To obtain spatial information by image processing, we need to track vehicles in the whole area of traffic scene. Image detector system based on global tracking consists of video input, vehicle detection, vehicle tracking, and traffic information measurement. For video input, conventional approaches used auto iris which is very poor in adaptation for sudden brightness change. Conventional methods for background generation do not yield good results in intersections with heave traffic and most of the early studies measure only point information. In this paper, we propose user-controlled iris method to remedy the deficiency of auto iris and design flame difference-based background generation method which performs far better in complicated intersections. We also propose measurement method for spatial traffic information such as interval volume/lime/velocity, queue length, and turning/forward traffic flow. We obtain measurement accuracy of 95%∼100% when applying above mentioned new methods.

• Journal of Korean Society of Transportation
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• v.17 no.2
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• pp.149-162
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• 1999

One of the most important steps of the design, capacity and operation analysis stapes in the two-lane two way highways is the effect of heavy vehicle to traffic flow quality. This heavy vehicle's effect on traffic flow can be represented as PCE, which is the number of passenger cars that are displaced by a single heavy vehicle of a particular type under prevailing roadway, traffic, and control conditions. In this paper, we focus on the heavy vehicles effect on volume, speed, delay, and the maneuver of freedom which are major MOE's in traffic operation analysis and PCE criterion which should be measurable, determinable and able to reflect the traffic flow characteristics. Therefore, the objective of the paper is to determine the PCE criterion and to develop a new PCE determination method. In this study, delay is adopted as PCE criterion and, for calculation of delay, the highway is divided into the passing zone and the no-passing zone. PCE is determined by comparing the delay due to total traffic flow interaction with the delay due to a single heavy vehicle, Also, this paper proposes a new method to determine the average PCE on the highway that has the passing zones and no-passing zones.

• Journal of Korean Society of Transportation
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• v.14 no.3
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• pp.91-125
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• 1996

The purpose of this paper is comparatively to evaluate the confidence of Vehicle-Detector informations for various detectors in order to test to be possible the application of these to real time traffic signal control. The detectors which are tested for this study are Circle-Shaped Loop, Ultrasonic, Microwave and Image detector. The tested items for each detectors are traffic volume, degree of saturation for through and left turn movement, speed and queue length, etc. These items for each are tested at the field according to several situations, such as dry day, raining day, night and daytime. The result of these tests are performed comparative analysis and statistical examination in order to increase the confidence of the experiments.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.1
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• pp.74-81
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• 1998

It is not good joint that today's traffic control system that the course of traffic volume increase tendency is followed, in the traffic volume is approched into the time of my car. Accordingly when we analyzed the existing traffic signal control system, the traffic signal system is developed from the machine type that the motor was centered, to get up to date, to the intelligence electron signal control system. But yet, when we have a test and a A/S on the control circuit, the circuit that is designed to the center IC and ROM are complicated. Also, the time of pass lamp that the car line stream is going, can not extended automatically a time till the traffic volume is decreased to the same direction. This theme must be a real time intelligence control system that the time of pass lamp can extend aumatically. The circuit of sequence ladder diagram on the traffic signal control of a crossroads that is desinged, can be satisfied the complicated vehicle order. Therefore when the circuit is changed, the new developed system is economical with that dosen't needs any of components to require the circuit equipment, and the time is saved with needlessness of the circuit wiring again, and have a much trustworthy. The control method of pass signal lamp in the car line stream connecting among PLC and Relay and Temp Sensor, can be changed to hand operation and to semi-automation and to all-automation. New intelligence traffic signal system is composed with all-together system of T Sensor + Video Camera + IBM PC that is able to guiding the establishment of traffic order.

• Journal of Korean Society of Transportation
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• v.27 no.1
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• pp.7-16
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• 2009

Korea Highway Capacity Manual (2001) proposes only LOS(Level of Service) analysis method on non-control and two-way-stop intersections, not dealing with the analysis method on LOS for roundabouts, nor even including the term 'roundabout'. This study selects proper MOEs for roundabouts and criteria the LOS through simulation analysis. To attain this goal, the authors reviewed the methods to select proper MOEs in the first step, criteria the Los. For this study, the MOEs were chosen from existing literature, and used for the criteria. The MOEs to be applied to roundabouts in this research were entry traffic volume, v/c (volume/capacity) ratio, and average vehicle delays. The results showed that the maximum entry traffic volume(LOS F) at local one-lane roundabout was analyzed to be 1,700pcph and average vehicle delay 18 seconds LOS A was analyzed as 700pcph and average vehicle delay 3 seconds and v/c 0.41 in this case Maximum entry traffic volume(LOS F) at local area 2 lane roundabouts was analyzed as 2,900pcph and their average vehicle delay as 31 seconds LOS A was analyzed to be 1.500pcph and average vehicle delay 8 seconds, v/c 0.52.