• Journal of Korean Society of Transportation
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• v.28 no.1
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• pp.97-105
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• 2010

An All-red clearance interval(AR) has been operating with amber signal in order to avoid collision between vehicles which cannot come out of the intersections, vehicles coming in from the opposite direction, and pedestrians(bicycles) on the crosswalk during the signal conversion time at the intersections. Foreign nations have been analyzing AR's influences of traffic accidents. On the other hand, the similar research has not been conducted in the country. The objective of this paper, therefore, is to analyze the safety at the intersections with respect to the installation of AR through the hypothesis test. A before-and-after analysis has been performed for 10 intersections where applied AR. From the 95% of significance level, the results of Non-parametric Test show that the installation of AR improves a safety at the intersections. The results indicates that AR discharges vehicles passing through the intersections and control entering vehicles at the intersections.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.1
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• pp.1-12
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• 2015

Intrusive Vehicle Detectors have excellent detection performance compared to other types of detector, but disadvantages of high installation and maintenance costs, short life time due to greater damage to roads and paving materials. In contrast, Non-Intrusive Vehicle Detectors attached to the stationary pole have advantages because it does not damage the road surface and easy and less expensive to maintain. Despite these advantages, Non-Intrusive type detectors are still not been widely used in traffic signal control systems because of the low detection performance. In this study, a FMCW(Frequency Modulated Continuous Wave) radar Vehicle Detector was designed as an alternative detector for the signalized intersection, and the performance evaluation was presented by purpose applicability.

• The Journal of the Acoustical Society of Korea
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• v.41 no.2
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• pp.210-217
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• 2022

Passive source depth estimation has been studied for decades since the source depth can be used for target classification, target tracking, etc. The purpose of this paper is to solve the problem of ambiguity in the previous paper [S.-il. Cho et al. (in Korean), J. Acoust. Soc. Kr. 38, 120-127 (2019)] that source depth is estimated in two points. The patterns of phase shift of Channel Impulse Response(CIR) reflected in ocean surface and bottom is used for removing ambiguity of the source depth estimation, and after removing ambiguity, source depth is estimated at one point through the intersection of CIR. In order to extract CIR in case of unknown source signal and continuous signal or noise, Ray-based blind deconvolution is used. The proposed algorithm is demonstrated through numerical simulation in ocean waveguide.

• International Journal of Highway Engineering
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• v.16 no.2
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• pp.119-129
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• 2014

PURPOSES : The purpose of this study is to develop the U-turn accident model at 4-legged signalized intersections in urban areas. METHODS : In order to analyze the characteristics of the accidents which are associated with U-turn operation at 4-legged signalized intersections in urban areas and develop an U-turn accident model by regression analysis, the tests of overdispersion and zero-inflation are conducted about the dependent variables of number of accidents and EPDO (Equivalent Property Damage Only). RESULTS : As their results, the Poisson model fits best for number of accident and the ZIP (Zero Inflated Poisson) fits best for EPOD, the variables of conflict traffic, width of opposing road, traffic passing speed are adopted as independent variable for both models. The variables of number of bus berths and rate of U-turn signal time at which the U-turn is permitted are adopted as independent variable only for EPDO. CONCLUSIONS : These study results suggest that U-turn would be permitted at the intersection where the width of opposing road is wider than 11.9 meters, the passing vehicle speed is not high and U-turn operation is not hindered by the buses stopping at bus stops.

• International Journal of Highway Engineering
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• v.15 no.3
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• pp.177-189
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• 2013

PURPOSES: This study aims to suggest a proper left-turn treatment method for the bicycle traffic flow at four-legged intersections. METHODS: Four types of crossing methods are proposed and analyzed : (1) indirect left turn, (2) direct left turn, (3) direct left turn on a Bike Box, and (4) direct left turn on bike left turn lane. The VISSIM simulation tests were conducted based on forty-eight operation scenarios prepared by varying vehicle and bicycle traffic volumes. RESULTS : The results from the four-legged signalized intersections suggest that (1) the indirect left turn is appropriate when vehicle demand is high, (2) the direct left turn is efficient on most traffic situation but the safety is a concern, (3) the direct left turn on a Bike Box is appropriate when bicycle demand is high while vehicle demand is not, and (4) the direct left turn on a bike left turn lane is appropriate when both vehicle and bicycle demand are low. CONCLUSIONS : The direct left turn of bicycle provides more efficiency than the indirect left turn at the four-legged intersections but to apply the methods and to study more, advanced evaluation methods, related law, and insurance programs are needed.

• IEMEK Journal of Embedded Systems and Applications
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• v.15 no.3
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• pp.119-127
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• 2020

The detection and recognition of abnormal driving becomes crucial for achieving safety in Intelligent Transportation Systems (ITS). This paper presents a feature extraction method based on spectral data to train a neural network model for driving behavior recognition. The proposed method uses a two stage signal processing approach to derive time-saving and efficient feature vectors. For the first stage, the feature vector set is obtained by calculating variances from each frequency bin containing the power spectrum data. The feature set is further reduced in the second stage where an intersection method is used to select more significant features that are finally applied for training a neural network model. A stream of live signals are fed to the trained model which recognizes the abnormal driving behaviors. The driving behaviors considered in this study are weaving, sudden braking and normal driving. The effectiveness of the proposed method is demonstrated by comparing with existing methods, which are Particle Swarm Optimization (PSO) and Convolution Neural Network (CNN). The experiments show that the proposed approach achieves satisfactory results with less computational complexity.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.1
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• pp.121-131
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• 2020

Current traffic information is collected through a loop detector or an image detector. This method is influenced by weather and time, so a traffic information generation system is needed to replace it. A system for generating traffic information using a smartphone in a vehicle is proposed and the performance of the proposed method is verified through the collection rate and the travel time error rate obtained through field tests. In addition, we propose an algorithm for generating intersection traffic information for each direction of rotation, suggest ways to increase the amount of valid information, and confirm the results.

• Journal of Korean Society of Transportation
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• v.9 no.1
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• pp.19-28
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• 1991

This study aims to seize the differences in drivers' attitudes and to speculate about the attitudes which may be causally related to traffic accidents based on data collected from group survey questionnaire in the four countries. The questionnaire was composed of 9 problem areas and prepared in Japanese English and Korean languages. The survey was conducted in Japan Canada U.S.A and Korea in 1987 The present study analysed the driver's attitudes toward behaviour of pedestrians traffic signal and causes of traffic accidents. The main results are :(1) The order of high percentage of those who cited the pedestrians as major cause of accidents was Korea Japan, Canada and U,S,A This markes the very high number of accidents involving pedestrians in Korea. (2) The percentage of who answered that most drivers started before the sign changed to Go sign at an intersection were higher in Japan and Korea than in U.S.A (3) Regarding the caues of accidents if the drivers were to meet with an accident the percentage of responses attributing faults to themselves for the accident was very high in Japan. Korea came next. In contrast the percentage of responses attributing faults to others is higher in Canada and U.S.A than Japan and Korea.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1227-1232
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• 2017

In this study, we have studied a system to reduce the inconvenience and the accident rate at the intersection when the visually impaired use traffic information by using pressure sensor and ultrasonic sensor. By using the pressure sensor to light the strip LED, the driver recognizes the pedestrian, thereby reducing the accident rate. In addition to the pedestrian signal light information, the ultrasonic sensor and Bluetooth transmit the bus position information to the application so that the user can listen to the voice.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.161-172
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• 2008

The level of service (LOS) evaluation method of the Highway Capacity Manual (HCM) is limited to intersections with pre-timed signal operation, while advanced real-time traffic control systems have been expending in the field. This paper proposes a preliminary framework for LOS analysis at isolated intersections controlled by COSMOS, the real-time traffic control systems robustly utilizing the degree of saturation as basic inputs. The proposed LOS evaluation framework was devised with a pilot model developed to estimate the average cycle length and green times of COSMOS. The validation test showed that the proposed framework was able to accurately project the LOS, which was separately evaluated based upon field data.