• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.603-611
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• 2020

Potholes on the road directly affect drivers' safety, satisfaction, and vehicle damage. Thus, real-time detection and response are required. Increasing frequency of patrols allows for potholes to be detected and responded to quickly, but this takes much manpower, money, and time. In addition, potholes have different occurrence characteristics depending on the rain conditions, so it is necessary to consider the optimal frequency from an economic and road-service perspective. Therefore, a quantitative analysis was done on the effects of rainfall on the occurrence characteristics of potholes. Information on the persistence, impact of rainfall intensity, and weather information was collected over a long period. Based on the results, a risk-based, optimized, and changeable road-patrol strategy is presented. The analysis results show that the probability of pothole occurrence increases by 2.4 times in rainy weather. Furthermore, the impact continues for 3 days even after the rain stops. The probability of pothole occurrence increases by 0.46% per 1 mm of rainfall, and the occurrence characteristics react sensitively to even a small amount of rain of around 1 mm. It was concluded that road patrol is required at least once every three days for an effect-free period, while twice a day is needed for the "sphere of influence" period to achieve a 95% reliability level.ys for effect-free period, while twice a day for sphere of influence period to satisfy 95% reliability level.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.3
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• pp.73-87
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• 2023

Furnishing traffic safety information can contribute to providing hazard warnings to drivers, thereby avoiding crashes. A smart road lighting platform that instantly recognizes road conditions using various sensors and provides appropriate traffic safety information has therefore been developed. This study analyzes the short-term traffic safety improvement effects of the smart road lighting's tunnel traffic safety information service using surrogate safety measures (SSM). Individual driving behavior was investigated by applying the vehicle trajectory data collected with RADAR in the Anin Avalanche 1 and 2 tunnel sections in Gangneung. Comparing accumulated speeding, speed variation, time-to-collision, and deceleration rate to avoid the crash before and after providing traffic safety information, all SSMs showed significant improvement, indicating that the tunnel traffic safety information service is beneficial in improving traffic safety. Analyzing potential crash risk in the subdivided tunnel and access road sections revealed that providing traffic safety information reduced the probability of traffic accidents in most segments. The results of this study will be valuable for analyzing the short-term quantitative effects of traffic safety information services.

• International Journal of Highway Engineering
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• v.13 no.3
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• pp.195-202
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• 2011

The purpose of this study is to estimate the capacity of two-lane freeway work zone blocking one lane using traffic flow models of each vehicle-type. Firstly, three traffic flow models of three different vehicle-types were developed using the data collected from each at the beginning and the ending point of the work zone. For each model, the maximum flow rate of three vehicle-types were calculated respectively. Maximum flow rate at the work zone was recalculated using passenger car equivalent value and percentage of vehicle-type. Secondly, traffic flow model using passenger car equivalent volume data was developed using the data collected from each at the beginning and the ending point of the work zone. Maximum flow rate for the work zone was calculated along. Two values of maximum flow rates through the work zone were compared and evaluated as the capacity of the work zone. This study found that the maximum flow rate of the work zone at the beginning point was less than that at the ending point because of impedance such as lane changing behaviors before entering the work zone. The capacity of two-lane freeway work zone blocking one lane was estimated 1,800pcphpl.

• Journal of Korea Multimedia Society
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• v.8 no.11
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• pp.1496-1509
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• 2005

In this paper, an adaptive license plate recognition system which detects and recognizes license plate at real-time by using projected plane convolution and Decision Tree Classifier is proposed. And it was tested in circumstances which presence of complex background. Generally, in expressway tollgate or gateway of parking lots, it is very difficult to detect and segment license plate because of size, entry angle and noisy problem of vehicles due to CCD camera and road environment. In the proposed algorithm, we suggested to extract license plate candidate region after going through image acquisition process with inputted real-time image, and then to compensate license size as well as gradient of vehicle with change of vehicle entry position. The proposed algorithm can exactly detect license plate using accumulated edge, projected convolution and chain code labeling method. And it also segments letter of license plate using adaptive binary method. And then, it recognizes license plate letter by applying hybrid pattern vector method. Experimental results show that the proposed algorithm can recognize the front and rear direction license plate at real-time in the presence of complex background environments. Accordingly license plate detection rate displayed $98.8\%$ and $96.5\%$ successive rate respectively. And also, from the segmented letters, it shows $97.3\%$ and $96\%$ successive recognition rate respectively.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.6
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• pp.31-42
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• 2019

Among the driving information recorded in the event data recorder (EDR), the speed information of the vehicle before the traffic accident is a very important factor that determines the punishment of the driver of the accident vehicle, the identification of the offender and the victim, and the possibility of avoiding the accident. Also, by analyzing the EDR data, the deceleration of the accident vehicle can be analyzed. In this study, the results of the braking test of the previous study and the analysis of the EDR data of the traffic accident vehicle were compared to suggest an appropriate deceleration value applicable to the calculation of the stopping distance. As a result of the braking test of the vehicle equipped with ABS of the previous study, the average deceleration of the vehicle was 0.79g ~ 0.94g. In addition, the deceleration value was calculated from 0.92g to 0.94g in the recent automobile safety evaluation braking test conducted by the Korea Automobile Testing & Research Institute. In addition, the deceleration value of 0.55g ~ 0.71g was calculated through the analysis of EDR data performed in this study, and the value was smaller than the deceleration value measured in the braking experiment of the previous study.

• Fire Science and Engineering
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• v.33 no.3
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• pp.138-142
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• 2019

By securing golden time, this study analyzed the effects of an emergency vehicle priority system in Cheongju, North Chungcheong province. Until the scene of a fire is reached, severe obstacles in the street, such as traffic congestion, cars coming forward, non-cooperative vehicles etc., are significant. To solve these problems of road obstacles, it is essential to adopt an emergency vehicle priority system. From April 2017 to June 2018 (1 year and 2 months, 426 days), the dispatch time and date, fire truck moving distance and required time, traffic signal control section and pass time, and shortening time, were measured. This study selected 140 cases consisting of five heavy traffic and frequent dispatch routes out of 293 cases. The effects of the emergency vehicle priority system were excellent. Overall, it took 3 min 3 s to pass 1 km on an uncontrolled traffic signal section. On the other hand, it took 1 min 23 s to pass 1 km on the same section that was controlled. The shortening time to pass 1 km was 1 min 40 s, showing a 45.4% reduction. This means that the 15 min driving time can be reduced to 6 min and 49 s. From this result, an emergency vehicle priority system should be implemented nationwide as soon as possible.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.175-181
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• 2009

Intelligent Transportation Systems(ITS) enables road users to enhance efficiency of their trips in a variety of traffic conditions. As a significant part of ITS, information communication technology among vehicles and between vehicles and infrastructure has been being developed to upgrade current traffic data collection technology through location-based traffic surveillance systems. A wider and detailed range of traffic data can be acquired with ease by the technology. However, its performance level falls with environmental impediments such as large vehicles, buildings, harsh weather, which often bring about wireless communication failure. For imputation of vehicle trajectory data discontinued by the failure, several potential existing methods were reviewed and a new method to complement them was devised. AIMSUN API(Application Programming Interface) software was utilized to simulate vehicle trajectories data and missing vehicle trajectories data was randomly generated for the verification of the method. The method was proven to yield more accurate and reliable traffic data than the existing ones.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.5
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• pp.1087-1096
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• 2011

Vehicular Ad Hoc Network(VANET) using wireless network is offering the communications between vehicle and vehicle(V2V) or vehicle and infrastructure(V2I). VANET is being actively researched from industry field and university because of the rapid developments of the industry and vehicular automation. Information, collected from VANET, of velocity, acceleration, condition of road and environments provides various services related with safe drive to the drivers, so security over network is the inevitable factor. For the secure message authentication, a number of authentication proposals have been proposed. Among of them, a scheme, proposed by Jung, applying database search algorithm, Bloom filter, to RAISE scheme, is efficient authentication algorithm in a dense space. However, k-anonymity used for obtaining the accurate vehicular identification in the paper has a weak point. Whenever requesting the righteous identification, all hash value of messages are calculated. For this reason, as the number of car increases, a amount of hash operation increases exponentially. Moreover the paper does not provide a complete key exchange algorithm while the hand-over operation. In this paper, we use a Received Signal Strength Indicator(RSSI) based velocity and distance estimation algorithm to localize the identification and provide the secure and efficient algorithm in which the problem of hand-over algorithm is corrected.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7329-7334
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• 2015

This is to analyze of driver behavioral and the accident characteristics in rollover. The study period was January 2011 to May 2014 and the subject of study was 102 person who were drivers visited the emergency room. Research tool includes a damage information of the vehicle, accident mechanism, damage to the patient clinical information with the injury data from the ROAD Traffic Authority. For data analysis, SPSS 18.0 was used for t-test, ANOVA and Chi-square test. Injury Severity Score average score according to the vehicle type is 6.00 points in the smaller vehicle, at high vehicle 11.78 points, from the other vehicle that showed 14.70 points. Significant differences between the three groups did not show (P=.267). Men did not use a seat belt significantly compared to women(P=.007). Vehicle type and weather, this was no correlation with whether or not use the seat belt(P=.755, P=.793). But showed a tendency to smaller size vehicles drivers do not use a seat belt, the weather could see a little more inclined to use a seat belt rather than a sunny day. Finally, in rollover accidents as in other types of accident it was confirmed that the seat belt has a great influence on the damage.

• International Journal of Highway Engineering
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• v.9 no.3
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• pp.39-50
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• 2007

Barrier VII program is normally used for the design of flexible barrier, but if modelled properly it can be used for the analysis of vehicle impact to small sign posts. In this paper sign post is shown to be modelled as flexible barrier by combining beam and column elements at each beam node. Simulations with the Barrier VII program have been made for 7 impact cases composed of sign posts of circular and H section with rigidly connected support and breakaway support system. The impact speed used for the simulation ranged from 30km/h to 110km/h. The study shows that in the vehicle impacts to a circular sign post with high speed, the large deflection and high inertia force causes the sign plate to hit the windshield leading to a hazard to the occupants. It is also shown that impact to H section post results in small deflection of the post and abrupt velocity change and high deceleration of the impact vehicle causing severe damage to both the vehicle and occupants. Simulation study also shows that breakaway support system eliminates the potential danger of the vehicle impact to the rigidly connected small sign posts by reducing deflection of the post, abrupt change in velocity and deceleration level.