• International Journal of Highway Engineering
• /
• v.15 no.3
• /
• pp.85-92
• /
• 2013

PURPOSES: The purpose of this paper is to estimate expected effects on traffic operational and economic aspects of 2+1 roads application in Korea. METHODS : Micro simulation study using VISSIM 5.0 was used to analyze the operation efficiency of 2+1 roads compared to two-lane highways and four-lane highways. Some scenarios for various traffic volumes were set up in order to analyze the effect of 2+1 roads under various traffic situations. Also imaginary road networks were set up for each type of roads. The MOEs to measure the operation efficiency were selected with average travel speed and delay. For analyzing economic effect of 2+1 roads, construction cost of a specific imaginary 2+1 road was compared to construction cost of a four-lane highway with same conditions. RESULTS: The results of study show that a 2+1 road is more effective with 19 percents higher average travel speed and 39 percents lower average delay than a two-lane highway. In the economic analysis, construction costs to construct a 2+1 road are saved as approximately 26.4~40.7 percents when compared to construction of four-lane highway. CONCLUSIONS: It can be concluded that 2+1 roads can improve the traffic operational level of service for two-lane highways and 2+1 roads can be applied as an effective design alternative for higher-volume two-lane highways in Korea.

• Journal of the Korean Institute of Rural Architecture
• /
• v.17 no.3
• /
• pp.11-18
• /
• 2015

This study is aimed to clarify the transitional characteristics of old roads and alleys lasting more than 100 years(1915-2015) in traditional urban area(Seongan-dong) of cheongju, historic inland and castle city of Korea. Cheongju castle had been completely destroyed In 1915, and urban structures been also altered last 100 years from 2015 now. Periodically, after destruction of castle, existing roads were extended and transformed to straight line for connecting with around. Expanding urban area to all directions of castle boundary in 1930-40s, town planning were created. These projects were completed in 1960-70s, the street network was built as they are. Since the 1980s, changes had been occurred in the details such as an extension of the unexecuted roads, the opening of fire lane in a block, and etc. In change and construction of roads, urban district plan in 1939 and reorganization since 1967 were planned and established with the type, location, and width of the large, medium and small roads based on data before destruction of castle. Except the width of 25m Sajikro(large3-1) and Sangdangro(large3-8,9,10), the width of 15m Namsaro(medium2-1) and Namjuro (medium2-4) as an extension of the roads, the other roads were small roads equivalent to the existing roads, and so remain intact figure of streetscape. As such, roads of east-west and north-south cross type, roads showing the outline of Cheongju castle fortress, and alleys outside the south gate are sustained in Seongan-dong of cheongju as historic urban area, and also present roads are delicately executed to the existing urban fabric.

• International Journal of Highway Engineering
• /
• v.15 no.2
• /
• pp.131-138
• /
• 2013

PURPOSES : The intents of the study are to identify the accident factors and to demonstrate the potentials of tobit model as a tool to study the number of accidents on arterial roads segments. METHODS : This paper uses a tobit regression as a methodology to analyze the factors affecting the number of accidents. In pursuing the above goal, this study gives particular attentions to analyzing the data of 2,446 accidents (1,610 in major arterial roads and 836 in minor arterial roads) occurred on arterial roads in 2007 to 2010. RESULTS : First, 3 accident models which were classified by total arterial roads, major arterial roads and minor arterial roads, and were all statistically significant were developed. Second, the exclusive right-turn lane as common variable, and the number of accident, traffic volume, number of lanes, link length, rate of median, number of entrances, number of pedestrian crossings, number of curves, number of bus stops and exclusive left-turn as specific variables of the models were selected. Finally, the paired sample t-test could not be rejected the null hypotheses of three types of models. CONCLUSIONS : Using data from vehicle accidents on arterial roads, the estimation results show that many factors related to roadway geometrics and traffic characteristics significantly affect to the number of accidents.

• Journal of Korean Society of Transportation
• /
• v.9 no.1
• /
• pp.5-18
• /
• 1991

Two-Lane, two-way roads account for approximately 92% of total road length in Korea and accomplish the majority of regional transport activities. Nevertheless not too many research have been made on two-lane roads particularly efficiency related topics such as capacity and travel time studies. In this study a full scale data collection was conducted using video equippments on rural two-lane roads to determine capacity Passenger Car Equivalents(PCE) and Level of Service criterion. Various PC programs were utilized to reduce traffic data and Walker ME? and Headway Method were employed to determine PCE's for heavy vehicles. The reseach has shown that capacity and PCE's for two-land two-way roads in Korea are 3200 pcph and 1.1∼1.9 resectively. In addition percent time delay was used as the basis of developing Level of service criterion on two-lane roads in Korea.

• Journal of the Society of Disaster Information
• /
• v.7 no.1
• /
• pp.1-11
• /
• 2011

Plans of underground roads have been established, and the possibilities of underground road constructions have been growing in Korea. However, the study on characteristics of underground roads, the enactment of law, and the establishment of design criteria haven't been conducted so far, if any. Based on these backgrounds, the paper presents the basic direction on the construction method of underground roads. It also investigates the needs and characteristics of underground roads and reviews domestic and foreign examples. Major results by implementing the research are as follows: 1) when selecting the route of underground roads, the use of underground space, technical aspects, and traffic systems should be comprehensively considered; 2) the design speed of underground roads will be 10km/h above the speed limit to secure safety; 3) disaster prevention facilities should be planned to connect high traffic management system for coping with unexpected situations. Although this study has a limitation that hasn't reflected the driver's characteristics on new spaces such as underground roads, it has some significance that it suggests the major reviewing issues on the construction of underground roads, and presents the direction through the previous study.

• Journal of Korean Society of Transportation
• /
• v.31 no.2
• /
• pp.3-10
• /
• 2013

Two-lane roads that occupy more than a half of rural highways in Korea have operational problems such as traffic congestion problems due to relatively high traffic volume and safety problems due to overtaking risks in two-lane highways. To solve these problems, a 2+1 road pattern that enables to improve traffic safety and operational efficiency of two-lane highways has been applied in Europe. In this study, in-depth applicability of 2+1 roads to Korean rural highways was investigated based on review results of the successful experience of European 2+1 roads. Then, given the Korean two-lane highway conditions, the service traffic volumes for Korean 2+1 roads was estimated. The analysis results showed that 17,000 veh./day might be the maximum traffic volumes for Korean 2+1 roads.

• Journal of Korean Society of Transportation
• /
• v.24 no.6 s.92
• /
• pp.33-43
• /
• 2006

This research is to the selection of optimal probability distribution as well as the estimation for design hourly factor in consideration of traffic characteristic, such as road function, lane number and AADT. To accomplish the objectives, we are applied to various probability distribution using traffic data that observed at permanent traffic count points in 2005. The parameters or the selected 14 probability distribution were estimated based on the method of maximum likelihood and the validity condition of the estimated parameter The goodness-of-fit test, such as chi-square test. was performed as well as the estimation of design hourly factor. As a result, An appropriate distributions of each case were selected : Pearson V for two lane of rural roads, LogLogistic for the four lane of rural roads, LogLogistic for the urban roads, Extreme value for recreation roads. And optimal K factor are as following : $0.1{\sim}0.2 $ for two lane of rural roads, $0.09{\sim}0.14$ for the four lane of rural roads. $0.07{\sim}0.13$ for the urban roads, $0.1{\sim}0.2$ for recreation roads.

• Journal of the Korean Institute of Rural Architecture
• /
• v.17 no.2
• /
• pp.1-8
• /
• 2015

The study is to find regional characteristics of the old town of Jeju city, "Mu-gun-sung," through researches of the status of the spatial structure in the cul de sac roads of the area. In particular, the status and characteristics of the area are clearly defined with the typology of the cul de sac roads based on the urban renewal regulations. The results are listed as follows: First, there are buildings from various periods in the area. Second, it is comparatively analyzed that there are the similarities and differences in Collaborative Development based on a neighborhood plan in Japan and Korea which pursue conservative renewals of the cule de sac roads. Third, the status and characteristics of the area are clarified through the analysis of the types of the cul de sac roads.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.57 no.2
• /
• pp.47-56
• /
• 2015

At the present, the mechanized form roads pavement was constructed with plain concrete. Mostly, it was used by welded wire mesh for preventing crack. Cellulose fibers for the reinforcement of concrete offer relatively high levels of elastic modulus, fiber count (per unit weight), specific surface, and bond strength to cement-based materials. The construction of concrete pavement confirmed that cellulose fiber reinforced concrete was applicable to mechanized form roads pavement. In the study, cellulose fibers were used here at 0.08 % volume fraction, which is equivalent to a fiber content of $1.2kg/m^3$. Cellulose fiber reinforced concrete were compared with plain concrete. Field test results indicated that cellulose fiber reinforced concrete showed slightly to increase of 28 days compressive strength and improved the initial strength. it tended to increase of splitting tensile strength. Test results showed that the slump and air content tend to decreased. but, the variation of air contends is very little. Also, construction cost of cellulose fiber reinforced concrete is less than about 25.7 % the case of welded wire mesh previously used. Therefore, The cost reduction is expected to be possible in construction site by mechanized form roads pavement.

• Journal of Korean Society of Transportation
• /
• v.14 no.2
• /
• pp.7-29
• /
• 1996

Traffic flow characteristics is analysed on eight multi-lane roads which are unsignalized in urban areas. Data of traffic flow rates by classification and average speed were gathered every ten minutes interval for twenty-four hours. Machine (NC-90A) was used to acquire the field data. The major purpose of this study is to build up speed-density models on urban arterial roads. Five different kinds of models were tested. Those models are Greenshields' model, Greenberg's model, modified Greenberg's model, Underwood's model and Drake's model. The modified Greenberg's model fits best at six points and the Greenshield's model fits best two points out of eight points. The breakpoint(Kb) of modified Greenberg's model is between 10 and 32 pcphpl. Capacity drawn from speed-volume relationships were appeared to be arround 2,000 and 2,200 pcphpl at the Hannam Bridge and the Hannam Overpass and 1,100 and 1,700 pcphpl at Namsan Tunnel(No1) and the beginning point of Gyeong-Bu Expressway.