• Journal of Korean Society of Transportation
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• v.27 no.1
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• pp.143-155
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• 2009

A dynamic traffic assignment (DTA) has recently been implemented in many practical projects. The core of dynamic model is the inclusion of time scale. If excluding the time dimension from a DTA model, the framework of a DTA model is similar to that of static model. Similar to static model, with given exogenous travel demand, a DTA model loads vehicles on the network and finds an optimal solution satisfying a pre-defined route choice rule. In most DTA models, the departure pattern of given travel demand is predefined and assumed as a fixed pattern, although the departure pattern of driver is changeable depending on a network traffic condition. Especially, for morning peak commute where most drivers have their preferred arrival time, the departure time, therefore, should be modeled as an endogenous variable. In this paper, the authors point out some shortcomings of current DTA model and propose an alternative approach which could overcome the shortcomings of current DTA model. The authors substitute a traditional definition for time-dependent OD table by a new definition in which the time-dependent OD table is defined as arrival time-based one. In addition, the authors develop a new DTA model which is capable of finding an equilibrium departure pattern without the use of schedule delay functions. Three types of objective function for a new DTA framework are proposed, and the solution algorithms for the three objective functions are also explained.

• Fire Science and Engineering
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• v.30 no.1
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• pp.130-137
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• 2016

The purpose of this study is to investigate the circumstances surrounding collisions involving ambulances with an aim to improving the safe operation of emergency services. Collisions are relatively common within paramedic emergency services. We analyzed the time, injury site, and any other specific factors of 908 collisions occurring within four cities. Within our study 29.6% of paramedics have been involved in accidents while responding to an emergency call, with the main cause of the accident being signal violation (35.7%), and is the other party's negligence (22.2%). 92.1% of these accidents occurred while the emergency lights were being operated. XX% of accidents took place in the afternoon, while xx% took place within the hours of xx:xx and xx:xx, during which time there is generally lower levels of traffic, which can cause severe brain and neck damage of 14.4% but the other part is 62.1%. (Ed note; this is not clear at all. 14.4% of collisions resulted in severe head and neck injuries, while 23.5% of collisions resulted in no injury. According to the respondents, defensive driving (xx%), observance of traffic laws (xx%), safe driving habits (xx%)to paramedics were the most critical factors in evading collision. Signal passes were identified as the most common cause of collision (70.1%). Although the majority of collisions occurred while the emergency lights were operational, the damage can cause severe damage at the time of accident occurred.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.6
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• pp.96-106
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• 2020

To solve the limitation of traffic monitoring that occur from embedded sensor such as loop and piezo sensors, the thermal imaging camera was installed on the roadside. As the length of Class 1(passenger car) is getting longer, it is becoming difficult to classify from Class 3(2-axle truck) by using an embedded sensor. The collected images were labeled to generate training data. A total of 17,536 vehicle images (640x480 pixels) training data were produced. CNN (Convolutional Neural Network) was used to achieve vehicle classification based on thermal image. Based on the limited data volume and quality, a classification accuracy of 97.7% was achieved. It shows the possibility of traffic monitoring system based on AI. If more learning data is collected in the future, 12-class classification will be possible. Also, AI-based traffic monitoring will be able to classify not only 12-class, but also new various class such as eco-friendly vehicles, vehicle in violation, motorcycles, etc. Which can be used as statistical data for national policy, research, and industry.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.3
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• pp.1-17
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• 2018

Over the past five years (2010-2014), the total number of traffic accidents has decreased from 226,878 to 223,552 with decrease of 0.37 percent each year. The death toll has also decreased from 5,505 to 4,762. However, the number of rental car accidents and fatalities has been steadily increased. Despite of its growth, no previous study has been conducted on rental car accident severity. This study analyzed data of 18,050 rental car accidents in South Korea collected from 2010 to 2014 and then processed in order to identify which factors could affect the accident severity. Seventeen factors related to rental car accident severity were grouped into four categories: driver, vehicle, roadways and environment. As a result of the ordered probit model analysis, fourteen variables excluding age, intersection, and day of week were found to affect the severity of rental car accidents. The results of the study summarized as follows. First of all, violation of traffic regulations such as speeding increase the severity of rental car accidents. Secondly, rental accident severity is higher at curved sections of complicated roadway, which the driver's field of view is impaired. The results of this study can be used to reduce the severity of rental car accidents in transportation safety.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.5
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• pp.105-112
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• 2011

Delay reduction of vehicles at the intersection is highly dependent on the signal operation method. Improper traffic operation causes the violation of the traffic regulations and increasing traffic congestion. Delay because of congestion has contributed to the increase in carbon dioxide in the atmosphere. The focus of this paper is to measure the amount of carbon dioxide when the intersection is changed to roundabout. Even though, Intergovernmental Panel on Climate Change(IPCC) recommends Tier 1 method to measure the amount of greenhouse gas from vehicles, this paper used Tier 3 method because we could use the data of average running distance per each vehicle model. Two signalized intersections were selected as the study area and the delay reductions of roundabout operation were estimated by VISSIM microscopic simulation tool. The control delay for boksu intersection reduced from 28.6 seconds to 4.4 seconds and the KRIBB intersection sharply reduced from 156.4 seconds to 23.6 seconds. In addition, carbon dioxide for two intersections reduced to 646.5 ton/year if the intersection is changed to roundabout. Future research tasks include testing the experiment for networks, as well as for various intersection types.

• Journal of Korean Society of Transportation
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• v.25 no.4
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• pp.89-98
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• 2007

Nowadays, aggressive driving is a common driving behavior and it is raised as a dangerous factor for both drivers and passengers. However, it is hard to find studies on aggressive driving in Korea, and even the definition of aggressive behavior is not clearly explained. In this study, the term "aggressive behavior" is defined based on previous studies, and the significance of several psycho-social factors which affect aggressive driving were verified with the 'habit' factor from the Theory of Planned Behavior (TPB). In the pilot study, domestic drivers reported that aggressive behaviors included speeding, traffic light signal violation, and improper passing (cutting drivers off when passing). In this study, controlling the demographic characteristics of these three aggressive behaviors, the authors explored the relationship of the behaviors with TPB factors such as the habit factor. Consequently, in the case of drivers' intentions for speeding and traffic light signal violations, subjective norm, perceived behavioral controllability, and habit were significant factors. In the case of intentions for improper passing, only perceived behavioral controllability and habit were significant. In speeding behavior and traffic light signal violations, only habit was significant besides intention; however, in improper passing, both perceived behavioral controllability and habit were significant besides intention. The authors also tested an alternative model including TPB and habit factors for three types of aggressive driving. Finally, there are several implications for a possible intervention program for aggressive driving, though there are some limitations of the study.

• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.6
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• pp.7-20
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• 2017

The advancement of cloud and big data and the considerable growth of traffic have increased the complexity and problems in the management inefficiency of existing networks. The software-defined networking (SDN) environment has been developed to solve this problem. SDN enables us to control network equipment through programming by separating the transmission and control functions of the equipment. Accordingly, several studies have been conducted to improve the performance of SDN controllers, such as the method of connecting existing legacy equipment with SDN, the packet management method for efficient data communication, and the method of distributing controller load in a centralized architecture. However, there is insufficient research on the control of SDN in terms of the quality of network-using applications. To support the establishment and change of the routing paths that meet the required network service quality, we require a mechanism to identify network requirements based on a contract for application network service quality and to collect information about the current network status and identify the violations of network service quality. This study proposes a method of identifying the quality violations of network paths through ontology to ensure the network service quality of applications and provide efficient services in an SDN environment.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.1
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• pp.182-192
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• 2022

Motorcycle accidents are increasing at an average annual rate of 10.01%, and fatalities are also increasing by 2.64%. Enforcement cameras are installed to enforce safe driving of more-than or equal-to four-wheeled vehicles on the road. Even though the main purpose of this enforcement camera is to disencourage the speed violation of all types of vehicle, one cannot expect complete enforcement by these cameras. In particular, enforcement of the motorcycle should rely on on-site activities through the input of on-site personnel. Recently, to discourage the illegal acts of motorcycling, the National Police Agency introduced the 'National Police Agency SMART National Report'. However, it is necessary to prepare an appropriate practical plan to maximize the effect of enforcement requiring continuous manpower management. This study proposed four types of rider certification IDs for delivery motorcycles. These IDs are institutional devices to manage delivery motorcycle riders. In addition, a experiment on enforcement was conducted using those license ID systems for delivery motorcycles. This experiment confirmed through the image-processing program (D-MESO) if one of the systems was possible to implement for enforcement on the delivery motorcycle rider's license.

• Journal of the Korea Safety Management & Science
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• v.15 no.4
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• pp.113-121
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• 2013

The rate that women's EMTs(emergency medical technicians) in fire department occupy is increasing, but my general plan is aimed at suggesting the improving plan for the working environment of women's EMTs paying attention to the duty stresses of increasing women's EMTs, because improvement for the working environment of women's EMTs is being proceeded slowly. I suggested my improving plan for solving the working stress on the basis of a survey of the Recognition against women's EMTs as follows. Firstly, I suggested that physical strength of women's EMTs should be managed well continually via program establishment and a defined evaluation not only by employing a professional person in charge for physical strength in firehouse, but also by replenishing the suitable number for the urgent mobilization. Secondly, I suggested that the suitable number for the urgent mobilization should be increased to 3 including an ambulance driver. Thirdly, I suggested necessity such as the fruitful education and the creation of circumstances that can focus on education for improving participation rate, development of various new educational program, incentive program and penalty. finally, I suggested the fact that is related to the actual re-amendment of the concerned law and ordinance such as not only the smooth treatment of penalty for a traffic signal violation of ambulance and the legal remedy system due to aggravation of a patient's condition during a first-aid course, but also workshop and meeting among the periodical EMTs and administration of special therapy program and sufficient recess.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.5
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• pp.7-14
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• 2012

We frequently confront with cars interfering into our lane on the ramp. We suffered from serious traffic congestion due to the interfering cars. But the police enforcement has not done actively because it's hard to enforce. In this study, we have evaluated the systems to enforce cutting-in cars through the field test. Generally, the image processing method depends on the weather. To overcome this limitation we proposed a new algorithm combined with section detection method. In the filed test we concluded the results as follows. Whereas the violation detection rate of the general image processing was 58.2%, a new algorithm proposed by this study was 74.5%. And, an error rate enforcing vehicles that do not violate was 0.0%. Also, we can use the existing facilities, such as street light because of compact and lightweight systems which are integrated camera with controller. Therefore, we concluded that it is possible to enforce the interfering Cars using vehicle enforcement systems.