• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.3
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• pp.153-164
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• 2018

Calculating the relevant length of left turn storages in urban intersections is very crucial in road designs. A left turn lane consists of deceleration lanes and left turn storages. In this study, we developed methods for calculating relevant lengths of left turn storages that vary at each intersection using UAV (Unmanned Aerial Vehicle) spatial images. Problems of conventional design techniques are applying the same number of left turn vehicles (N) using Poisson distribution without considering land use types, using a vehicle length that may not be measurable when applying the length of waiting vehicles (S), and using same storage length coefficient (${\alpha}$), 1.5, for every intersections. In order to solve these problems, we estimated the number of left turn vehicles (N) using an empirical distribution, suggested to use headways of vehicles for (S) to calculate the length of waiting vehicles (S) with a help of using UAV spatial images, and defined ranges of storage length coefficient (${\alpha}$) from 1.0 to 1.5 for flexible design. For more convenient design, it is suitable to classify two cases when possible to know and impossible to know about ratio of large trucks among vehicles when planning an intersection. We developed formula for each case to calculate left turn storage lengths of a minimum and a maximum. By applying developed methods and values, more efficient signalized intersection operation can be accomplished.

• Journal of the Society of Disaster Information
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• v.11 no.4
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• pp.597-606
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• 2015

Until now, u-turn lane installation methods have been studied variously. But, There is no specific standard yet. This study ranges are commercial area in Incheon metropolitan city through field investigation and presents specific design standard for efficient operation of left turn using a field data through calculating relevant permitted u-turn lane length and minimum separation distance from the front intersection to starting point of permitted u-turn lane in urban signalized intersections in commercial area. Relevant permitted u-turn lane length is found to be 32m and minimum separation distances from the front intersection to starting point of permitted u-turn lanes are 72m, 40m, 24m in case of 1 left turn lane, 2 left turn lanes and 3 left turn lanes respectively. By comparing result values and field data, they had a large difference under the similar situations in their lengths. This result is caused of no specific standard about design of u-turn lanes. If results of this study applied to design of u-turn lanes, signalized intersections in urban commercial areas would be operated more safety and efficiently.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.2
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• pp.65-78
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• 2015

An important factor in assessing the beneficial qualities of a city's intersection spaces can be measured by examining a pedestrian's approach to the space and calculating the openness observed in the overall design of adjacent buildings. These spaces are influential, since they offer opportunities for pedestrians to spend time and take in views of the surrounding environment. The intersection of horizontal components in cities such as Bundang-si and Suwon-si can provide a sense of openness or greenness. We believe that there is a need for careful analysis and study of such components, as defined by designations in Bucheon-si research, and that this study can give important insights for future urban planning and design. When assessing the openness of an intersection, a key variable is the reported rate of perforation, which factors into the greenness of a space. Because of the large and varied scope of this research, this rate is highly variable, as there were many differences between each site. In descending order of average ratios: Seongnam-si, 41.79% > Bucheon-si, 35.40% > Suwon-si, 30.42%. The data compared for each city was divided into study sites selected at downtown locations as well as in urban outskirts. Openness and greenness were analyzed at each downtown and outskirt site. A summary of the results shows a decreased openness average of -2.63% in downtown locations versus outskirt. The greenness ratios in urban outskirt areas were 4.86% greater than downtown locations on average. As it relates to the results of this analysis of openness, the comprehensive property zoning for each city was determined as a ratio of residential to commercial designations. This study analyzes view points within urban cross intersections in the downtown landscape. It presents basic data and research directions to promote a better environment with regard to openness, and consists of an analysis of the relationship between a variety of physical components.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.115-131
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• 2022

Carbon dioxide (CO₂) emissions from the transportation sector in South Korea accounts for 16.5% of all CO₂ emissions, and road transportation accounts for 96.5% of this sector's emissions in South Korea. Hence, constant research is being carried out on methods to reduce CO₂ emissions from this sector. With the emerging use of smart crossings, attempts to monitor individual vehicles are increasing. Moreover, the potential commercial deployment of autonomous vehicles increases the possibility of obtaining individual vehicle data. As such, CO₂ emission research was conducted at five signalized intersections in the Gangnam District, Seoul, using data such as vehicle type, speed, acceleration, etc., obtained from image detectors located at each intersection. The collected data were then applied to the MOtor Vehicle Emission Simulator (MOVES)-Matrix model-which was developed to obtain second-by-second vehicle activity data and analyze daily CO₂ emissions from the studied intersections. After analyzing two large and three small intersections, the results indicated that 3.1 metric tons of CO₂ were emitted per day at each intersection. This study reveals a new possibility of analyzing CO₂ emissions using actual individual vehicle data using an improved analysis model. This study also emphasizes the importance of more accurate CO₂ emission analyses.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.4
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• pp.37-49
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• 2014

This paper aims to interpret the transformation process of town plan of Gosan-up(高山), which was provincial administrative focus town in Josun dynasty, basing on morphological viewpoint. Morphological concepts, such as morphological frame, urban plan, kernel, colonization, route system, fixation line, fringe belt, plan unit & plan division, morphological period derived from the study of Conzen, M.R.G. and Caniggia, G. epidome district, break point, broken plot, urban fallow, privatization are adopted for the interpretation of urban form. Morphological period of Gosan can be divided in four ; formation of kernel & morphological structure, disintegration & redevelopment of the kernel, augmentative development of the kernel & formation of modern epidome district, outwards expanding of urbanized area, transition & reorganization of epidome district. Especially public leading projects such as construction of new regional connection road and public facilities such as myeon(township) office, agricultural cooperatives federation office, market, are main factors of morphological transformation of townplan. In the early stage, under the Japanese imperialism, construction of the new matrix route(Gosan-ro) through the kernel and followed planned routes gave way to disintegrating traditional areal plan unit and forming small block plan units in administrative facilities area. And linear plan units with commercial buildings were formed along the new matrix route and planned route adjacent to periodical market. In the latter stage, with development of public facilities, private sectors' large circulation institution and terminal outside the kernel with planned routes formed areal block based plan units with commercial and public buildings. And part of the spatial area with the linear plan unit were turned into urban fallow. With the transformation of town plan, new roads outside the kernel have substituted for traditional fixation line of waterway with road and topographical feature. Fringe belts were made successively along the new road and around the major intersections outside of existing urbanized area. Land use in fringe belts, constituting of outer locational tendency early on formation, was gradually replaced with commercial & business buildings.

• International Journal of Highway Engineering
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• v.20 no.2
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• pp.75-85
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• 2018

PURPOSES : This study aimed to analyze traffic accidents at circular intersections, and discuss accident reduction strategies based on land use and vehicle type. METHODS : Traffic accident data from 2010 to 2014 were collected from the "traffic accident analysis system" (TAAS) data set of the Road Traffic Authority. To develop the accident rate model, a multiple linear regression model was used. Explanatory variables such as geometry and traffic volume were used to develop the models. RESULTS : The main results of the study are as follows. First, it was found that the null hypotheses that land use and vehicle type do not affect the accident rate should be rejected. Second, 16 accident rate models, which are statistically significant (with high $R^2$ values), were developed. Finally, the area of the central island, number of speed humps, entry lane width, circulatory roadway width, bus stops, and pedestrian crossings were analyzed to determine their effect on accidents according to the type of land use and vehicle. CONCLUSIONS : Through the developed accident rate models, it was revealed that the accident factors at circular intersections changed depending on land use and vehicle type. Thus, selecting the appropriate location of bus stops for trucks, widening entry lanes for cars, and installing splitter islands and optimal lighting for motorcycles were determined to be important for reducing the accident rate. Additionally, the evaluation showed that commercial and mixed land use had a weaker effect on accidents than residential land use.

• Journal of the Korean Society of Safety
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• v.33 no.1
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• pp.135-141
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• 2018

Rotary that causes traffic delays and safety issues by high-speed entry vehicles is currently being improved to roundabout. The operational difference between rotary and roundabout can cause driver's confusion and traffic accident. The purpose of this study is to develop the accident rate models which explain the factors related to the accidents by land use and intersection type. The main results are as follows. First, the null hypotheses that the type of land use and two intersections do not affect the accident rate are rejected. Second, the conflicting factors such as the number of crosswalk and bicycle lane should be carefully considered to reduce traffic accident at rotary. In the case of roundabout, greater than 3.5 m in circulatory lane width and two circulatory lane are analyzed to be important to prevent the accidents. Finally, the commercial and mixed areas are evaluated to be weak to traffic accidents than residential area.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.75-83
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• 2015

PURPOSES : This study deals with the traffic accidents classified by the traffic analysis zone. The purpose is to develop the accident density models by using zonal traffic and socioeconomic data. METHODS : The traffic accident density models are developed through multiple linear regression analysis. In this study, three multiple linear models were developed. The dependent variable was traffic accident density, which is a measure of the relative distribution of traffic accidents. The independent variables were various traffic and socioeconomic variables. CONCLUSIONS : Three traffic accident density models were developed, and all models were statistically significant. Road length, trip production volume, intersections, van ratio, and number of vehicles per person in the transportation-based model were analyzed to be positive to the accident. Residential and commercial area ratio and transportation vulnerability ratio obtained using the socioeconomic-based model were found to affect the accident. The major arterial road ratio, trip production volume, intersection, van ratio, commercial ratio, and number of companies in the integrated model were also found to be related to the accident.

• Journal of Korean Society of Transportation
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• v.32 no.6
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• pp.615-627
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• 2014

In this study, nonhierarchical K-mean cluster analysis is used to classify the types of 230 local governments and the Mann-Whitney U test and Kruskal-Wallis analysis are used to analyze the characteristics of pedestrian accidents by region types. With empirical analysis of pedestrian accidents, this study suggests improvements of walking environments reflecting local characteristics. Type 1-A (relatively dominant urban commercial areas), Type 1-B (predominantly urban residence) and Type 2 (rural areas) have been classified using nonhierarchical K-mean cluster analysis. According to the results, pedestrian accident rate on community roads was more than 60% for all types and incidence rate in rural areas was higher than that in urban areas. In addition, pedestrian accidents of Type 1-B have been found to occur more frequently than Type 2 in intersections and crossings, while the number of roadside casualties for Type 2 was highest.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.4
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• pp.26-40
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• 2018

The aim of this research is to analyze factors affecting bicycle accidents using the PLS structural equation. Accident types in this study were categorized into total accidents, serious injuries including death, and light injuries which occurred at nationwide Si Gun Gu. It was found that urbanization was the main factor for bicycle accidents through the accident models developed in this study. Population, ratio of economically active population, density of intersections, ratio of urbanized area, commercial and industrial land-uses, number of drive license holders, number of education institutions, number of parks were the main factors causing bicycle accidents. Besides, length of bicycle roads, number of bicycles, and ratio of bicycle as mode choice also increased bicycle accidents.