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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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International Journal of Highway Engineering
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Journal DOI :
Korean Society of Road Engineers
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Volume & Issues
Volume 13, Issue 4 - Dec 2011
Volume 13, Issue 3 - Sep 2011
Volume 13, Issue 2 - Jun 2011
Volume 13, Issue 1 - Mar 2011
Selecting the target year
The Study on the Optimized Earthwork Transfer Path Algorithm Considering the Precluded Area of Massive Cutting and Banking
Kang, Tae-Wook ; Cho, Yoon-Ho ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 1~8
DOI : 10.7855/IJHE.2011.13.4.001
The purpose of this study is to suggest the optimized transfer algorithm of earthwork considering the precluded area such as the lake, bogs. The earthwork transfer plan in massive cutting and banking should be established because of affecting the construction cost highly. Until now, there was the study about the optimized earthwork transfer model considering the OR(Operating Research). but isn't the study about the model considering the precluded area such as the lake, bogs. In most cases, the engineer adjusts the earthwork transfer path considering the precluded area, manually. The presented model suggests to calculate various visibility paths with
algorithm after converting the precluded area to polygon topology. By using this paths, the minimum cost path to optimize the earthwork transfer can be obtained. In this study, the validity of the model was proved as implementing the system for the optimized earthwork transfer considering the precluded area.
Study on Improvement Method and Performance Analysis About Occupied Existing Roadside Barriers in Expressway
Joo, Jae-Woong ; Jang, Dae-Young ; Ha, Jong-Moon ; Park, Je-Jin ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 9~17
DOI : 10.7855/IJHE.2011.13.4.009
It is possible to set up the Roadside Barrier which is suitable for Performance Evaluation Criteria by domestic standard. But a number of section of expressway roadside have old guardrail that was installed before reform the guideline. These poor performance guardrails threaten driver's life. There is lots of difficult problem to change old guardrails that are installed 2,777km in expressway of whole road side at the same time. Especially budget problem. The purpose of study is to develop performance improvement guardrails by the minimum reinforcement. In this study, guardrail improvement method(SB1, 3, 5 grade) is developed through crash simulation using LS-DYNA 3D and vehicle crash test. And it's expected not only to decrease of collision accident but to increase safe level. Of course one thing that can't be missing is to reduce a lot of budget of guardrail change.
Laboratory and Field Performance Evaluation of Acryl Resin Based Solar Radiation Reflective Pavement
So, Kyung-Rock ; Lee, Hyun-Jong ; Baek, Jong-Eun ; Lee, Sang-Yum ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 19~28
DOI : 10.7855/IJHE.2011.13.4.019
This study developed a solar radiation reflection pavement, so called a cool pavement, to lessen the urban heat island effect by coating a pavement surface with acrylic resins mixed with light-colored pigments. From a laboratory test, simulating solar heating process in pavements, the cool pavement reduced more than
of pavement temperature at
compared to a control porous pavement. With the increase of the mixing ratio of the pigments to acrylic resins, the temperature reduction effect increased, but its workability became worse due to higher viscosity. As a result, an appropriate mixing ratio was determined as 15%. The cool pavement had better durability than the control pavement: One quarter of Catabro loss and twofold dynamic stability. Its adhesion was also higher enough not to be debonded under traffic loading. In-situ noise and friction tests conducted in two field sites showed that the cool pavement reduced its noise level by 3.7dB in average and increased its friction level by 30% compared to the control pavement. The permeability of the cool pavement was little lower than the control pavement, but higher enough to satisfy the minimum requirement for porous pavements.
A Study of Warm-Mix Asphalt's Bonding Properties on the Change of Asphalt Film Thicknesses
Yoo, In-Sang ; Cho, Dong-Woo ; Hwang, Sung-Do ; Rhee, Suk-Keun ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 29~40
DOI : 10.7855/IJHE.2011.13.4.029
Warm-Mix Asphalt(WMA) technologies have been developed since 15 years ago, which are internationally and domestically concerned with energy-saving and environmental-friendly technologies in public and private sectors of highway engineering. The performance of asphalt mass is traditionally evaluated by the penetration, viscosity, or Superpave tests. This research, however, is focused more on the properties depending on asphalt film thicknesses instead of evaluating asphalt mass behaviors by those tests. For this approach, a new testing protocol and analysis method are described by the bonding properties on each film thickness. This testing method and analysis tool are borrowed from those of DSR Moisture Damage test and applied by using ARES. The analysis results indicate that there is a limit film thickness between
, which causes significant changes of the properties. In addition, the results show that the property changes of Hot-Mix Asphalt(HMA) and WMA on the limit film thickness are also different. Therefore, it is suggested that the properties on thin film thicknesses between
should be considered in order to evaluate WMA properly.
Evaluation of Permanent Deformation Characteristics in Crushed Subbase Materials Using Shear Stress Ratio and Large Repeated Triaxial Compression Test
Lim, Yu-Jin ; Kim, In-Tae ; Kwak, Ki-Heon ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 41~50
DOI : 10.7855/IJHE.2011.13.4.041
It is well-known that pavement is easily damaged by several factors including permanent deformation and fatigue crack, causing service life of the pavement to be shorter than expected. It is very important to predict amount of permanent deformation for designing pavement and developing design method of pavement. A new model of permanent deformation of pavement materials based on concept of shear stress ratio has been proposed because the lower pavement materials are highly affected by shear strength of the material. In this study a large repetitive triaxial load test has been adapted for performing test of permanent deformation of crushed subbase materials. The test procedure which includes concept of shear stress ratio has been newly developed. Several important model parameters can be obtained from the test that can be used for making correct permanent deformation model of the material.
Development of Mechanistic-empirical Joint Spacing Design Method for Concrete Pavements
Park, Joo-Young ; Hong, Dong-Seong ; Lim, Jin-Sun ; Jeong, Jin-Hoon ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 51~59
DOI : 10.7855/IJHE.2011.13.4.051
Tensile stress occurs and random crack develops in concrete pavement slab when it contracts by variation of temperature and humidity. The tensile stress decreases and the random crack is minimized by sawcutting the slab and inducing the crack with regular spacing. The random crack, joint damage, decrease of load transfer efficiency are caused by too wide joint spacing while too narrow joint spacing leads to increase of construction cost and decrease of comfort. A mechanistic-empirical joint spacing design method for the concrete pavement was developed in this study. Structurally and environmentally weakest sections were found among the sections showing good performance, and design strengths were determined by finite element analysis on the sections. The joint width for which the load transfer efficiency is suddenly lowered was determined as allowable joint with referring to existing research results. The maximum joint spacing for which the maximum tensile stress calculated by the finite element analysis did not exceed the design strength were found. And the maximum joint width expected by the maximum joint spacing were compared to the allowable joint width. The new method developed in this study was applied to two zones of Hamyang-Woolsan Expressway being designed. The same joint spacing as a test section constructed by 8.0m of joint spacing wider than usual was calculated by the design method. Very low cracking measured at 6 years after opening of the test section verified the design method developed in this study.
Development and Calibration of a Permanent Deformation Model for Asphalt Concrete Based on Shear Properties
Lee, Hyun-Jong ; Baek, Jong-Eun ; Li, Qiang ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 61~70
DOI : 10.7855/IJHE.2011.13.4.061
This study developed a permanent deformation model for asphalt concrete based on shear properties. Repeated load triaxial compression (RLTC), triaxial compressive strength, and indirect tension strength tests were performed for the three types of asphalt mixtures at various loading and temperature conditions to correlate shear properties of asphalt mixtures to rutting performance. For the given mixtures, as testing temperature increased, cohesion decreased, but friction angle was insensitive to temperature at
or higher. It was observed that deviatoric stress, confining pressure, temperature, and load frequency affected the permanent deformation of asphalt mixtures significantly. The permanent deformation model based on shear stress to strength ratio and loading time was developed using the laboratory test results and calibrated using accelerated pavement test data. The proposed model was able to predict the permanent deformation of the asphalt mixtures in a wide range of loading and temperature conditions with constant model coefficients.
The Prediction of Remaining Life of Concrete Bridge Decks Using The Reliability Analysis
Park, Jung-Hee ; Lee, Sang-Soon ; Kim, Ji-Won ; Park, Cheol-Woo ; Lee, Dong-Hyun ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 71~79
DOI : 10.7855/IJHE.2011.13.4.071
Korean national highway has been increased 2 times more for the past ten years because of many highway geometric improvements and new routes since 2000. According to the reasons, maintenance cost has been increased continuously. Deterioration of concrete bridge decks caused by asphalt pavement deformation occupies a high proportion of overall bridge management budget. The number of current highway bridges has reached over 7,800 in 2011, and It is difficult to determine to some future budget. This study predicted the remaining life of concrete bridge decks using the reliability analysis based on Weibull distribution. and The expected future maintenance cost was estimated.
Experimental Analysis of Terminus and Horizontal Crack Behaviors in Continuously Reinforced Concrete Pavement
Cho, Young-Kyo ; Kim, Seong-Min ; An, Zuog ; Han, Seung-Hwan ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 81~91
DOI : 10.7855/IJHE.2011.13.4.081
This study was conducted to evaluate the necessity of the anchor lug system in continuously reinforced concrete pavement(CRCP) by comparing longitudinal displacements of CRCPs with and without anchor lugs, and to investigate the effect of horizontal cracking on CRCP performance by measuring the vertical displacements. The measurements before and after the anchor lug section was separated were conducted for 12 days in June, and for 14 days in August after the abrupt displacements according to cutting disappeared, respectively. This short term measurement results showed that when anchor lugs were installed, a daily displacement variation at any location was less than 0.1mm; therefore, longitudinal movements were negligibly small. When there were no anchor lugs, longitudinal displacements mainly occurred near the free end and the displacement variation was small; therefore, an expansion joint system seems to be employed at a CRCP terminus without installing anchor lugs. However, further studies are needed to verify the terminus behavior due to annual temperature changes. The horizontal crack width variation was ignorable and did not affect the vertical displacement of the slab. Therefore, the horizontal crack did not delaminate the slab and did not seem to reduce the structural capacity and performance of CRCP.
Evaluation of Color Coating Method for Color Maintenance of Color Asphalt Pavement
Park, Tae-Soon ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 93~101
DOI : 10.7855/IJHE.2011.13.4.093
The evaluation of various color coating methods for color maintenance of color asphalt pavement is conducted using the laboratory and field tests on the bus lane. The surface of color asphalt constructed on the bus lane is deteriorated such as changing color and decoloration and abrasion due to the passing of the traffic and time. The total of 9 coating methods were evaluated in this study. The laboratory tests included Ultra violet test, adhesion test and Taber abrasion test and the field tests were british pendulum test and visual survey. The results of tests showed that the different methods showed the their own engineering characteristics and it is dependant upon the main material used. The rubber epoxy material for the main material showed the satisfactory result among the methods tested. However, the performance of the coating methods after 100days are not satisfactory, decoloration, abrasion and peeling up are investigated and need to be studied for the further application in the field.
Improvement of Fatigue Model of Concrete Pavement Slabs Using Environmental Loading
Park, Joo-Young ; Lim, Jin-Sun ; Kim, Sang-Ho ; Jeong, Jin-Hoon ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 103~115
DOI : 10.7855/IJHE.2011.13.4.103
Concrete slab curls and warps due to the uneven distribution of temperature and moisture and as the result, internal stress develops within the slab. Therefore, environmental loads must be considered in addition to the traffic loads to predict the lifespan of the concrete pavement more accurately. The strength of the concrete slab is gradually decreases to a certain level at which fatigue cracking is generated by the repetitive traffic and environmental loadings. In this study, a new fatigue regression model was developed based on the results from previously performed studies. To verify the model, another laboratory flexural fatigue test program which was not used in the model development, was conducted and compared with the predictions of other existing models. Each fatigue model was applied to analysis logic of cumulative fatigue damage of concrete pavement developed in the study. The sensitivity of cumulative fatigue damage calculated by each model was analyzed for the design factors such as slab thickness, joint spacing, complex modulus of subgrade reaction and the load transfer at joints. As the result, the model developed in this study could reflect environmental loading more reasonably by improving other existing models which consider R, minimum/maximum stress ratio.
Study on the Performance Evaluation of Colored Asphalt Hot Mixtures through the Usage of Grain-typed Color Additive
Lee, Sang-Yum ; Ahn, Yong-Ju ; Mun, Sung-Ho ; Kim, Yeong-Min ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 117~122
DOI : 10.7855/IJHE.2011.13.4.117
Asphalt concrete pavement can be widely seen on urban streets, highways, parking lots, and bike trails. Asphalt concrete pavement is relatively temperature sensitive materials due to the viscoelastic behavior, which can be defined as flexible performance in summer and rigid performance in winter. In terms of maintenance, it can be fixed quite easily if damaged. In addition, asphalt concrete pavement is generally found to be black and grey in color. However, several colors can be adopted to change the appearance of plain old boring, black and grey. Generally, there are two types of color systems in hot mix asphalt concrete materials. One system uses colored cementitious material that is applied to pavement surface through coating the surface of the asphalt pavement. The major disadvantage to this system requires a careful skill set to be used on the construction site in order to prevent taking off the cementitious material. The other coloring system colors the asphalt hot mixtures through using color additives. The main advantage to this system is that the asphalt pavement layer is colored using the same techniques that are already used in paving. The disadvantage is that the colors are limited to mainly reds and browns. In this study, a suggested color additive was evaluated, based on rutting, moisture sensitivity, and fatigue cracking performance.
Determination of Multi-Lane Loading Factors for Vehicular Load of Bridges using Weigh-In-Motion Data
Hwang, Eui-Seung ; Nguyen, Thi Hang ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 123~132
DOI : 10.7855/IJHE.2011.13.4.123
The purpose of this study is to calculate and propose rational multi-lane loading factors for bridge design considering the probability of simultaneous truck passing in adjacent lanes and real truck weights. The probability of simultaneous truck passing is calculated by analyzing video image taken at various locations in highways and national roads. Weigh-In-Motion system data at two locations are used, which is combined with the probability of multiple presence to calculate the multi-lane loading factors for typical 2 lane and 5 lane bridges. Statistical properties of multi-lane loading factors are also calculated assuming that locations for video images and WIM data represent the overall traffic condition in the country. Results are compared with various design codes in the world and they show that the values are between the current Korea Bridge Design Code and AASHTO LRFD specification or Eurocode and are similar to Canadian Code.
Feasibility Evaluation of Number of Gyration for HMA and WMA Mixtures
Lee, Moon-Sup ; Yoon, Chun-Joo ; Kwon, Soo-Ahn ; Kim, Kwang-Woo ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 133~142
DOI : 10.7855/IJHE.2011.13.4.133
The objective of this study is to validate the number of gyrations of Superpave gyratory compactor(SGC) for compaction of hot-mix asphalt (HMA) and warm-mix asphalt(WMA) mixtures. Marshall compaction was also used for comparison purpose. The 13mm and 19mm aggregates of 1st class quality shape were used. A PG64-22 and a PG76-22 for HMA and a PG70-22 for WMA. Four compaction temperatures based on the suggested value were used for each binder using 100 gyrations for SGC and 75 blows per side for Marshall compactor. It was found that SGC compaction was somewhat better than Marshall compaction. The analysis of variance showed that two compactors were significantly different in air voids of 19mm mixtures at
level. The 13mm mixture did not show a significant statistical difference. When compacted at the temperature below a certain level, however, the compaction of two compactors were fond to be proor. Therefore, observing compaction temperature above the minimum level is important to secure proper compaction work. If the minimum temperatures were maintained, 100 gyrations, which was given for HMA of arterial road pavement by the Korean Guide, was found to be appropriate compaction, showing similar or better compaction work than 75 blows per side of Marshall compaction.
A Study of Roundabout Operation According to the Pedestrian Volume
Kim, Sang-Youp ; Choi, Jai-Sung ; Lee, Su-In ; Kim, Myung-Kyu ; Kim, Young-Il ; Jeon, Byeong-Kuk ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 143~150
DOI : 10.7855/IJHE.2011.13.4.143
Roundabouts, which belong to traffic circles, are intersections which are similar to the existing rotary form. Roundabouts recently have been constructed all around the world. And interests in roundabouts are increasing in Korea. However, there are lacks of research on pedestrian volume which has a great influence on operation efficiency of roundabouts in urban area. Therefore, this study suggests efficiency analysis and pedestrian signals in roundabouts according to the pedestrian volume. First, VISSIM simulation was organized to analyse volume of one lane roundabouts in urban area. Second, average delay of intersections was calibrated by VISSIM simulation dividing signalized intersections and non-signalized intersections depending on pedestrian volume. Finally, this study showed that roundabouts are suitable when pedestrian volume was under 200person/hr and traffic circles with a pelican signal are suitable when pedestrian volume was over 200person/hr. And when pedestrian volume and traffic volume are over 600person/hr and 1,500vph respectively, fixed signalized intersections fit well.
Qualitative Factor Analysis on Speed Reduction of Drivers in Expressways Tunnel Section
Park, Jun-Tae ; Lee, Soo-Beom ; Kim, Tae-Ho ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 151~158
DOI : 10.7855/IJHE.2011.13.4.151
Tunnel sections on the expressway are different from rest of sections on the expressway in terms of velocity, the number of passing cars, and vehicle density which, in particular, affect drivers' behavior before and after drivers pass through the tunnel. However, literature review reveals that former studies are too focused on quantitative indicator to consider qualitative aspects. Thus, this study tried to find out qualitative factors affecting speed reduction in tunnel sections based on questionnaire surveys and its analysis in tunnel sections selected by taking consideration of diverse conditions. Analysis showed that factors concerning tunnel configuration (lane width, shoulder width, and tunnel length) related to very long tunnels increasingly popular recently had some effects on reduced speed inside of tunnels. It appeared that visual environment such as visibility of tunnel entrance had an impact in speed reduction and vehicle speed tended to change according to lighting illumination level inside of tunnels. It is expected that continual investment would be made in technological development related to expressway tunnel design and service improvement based on this study.
A Fundamental Study for Design of Electric Energy Harvesting Device using PZT on the Road
Lee, Jae-Jun ; Ryu, Seung-Ki ; Moon, Hak-Yong ; Kwon, Soo-Ahn ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 159~166
DOI : 10.7855/IJHE.2011.13.4.159
Green house gas emissions are increasing as development of the industrial economy of the international community. Many countries in the world are endeavoring to reduce green house gas emissions under severe climate change. In order to protect grobal warming, government is trying to reduce green gas emissions under "Low Carbon Green Growth Policy" and investing climiate-firendly industries such as renewable energy harvesting. Renewable energy has been rapidly developing as a result of investment for development technology of using natural energy such as solar, wind, tidal, etc. There are lots of waste energy in the road space. However, nobody is not interested in waste energy from the road space. This paper present a fundamentally experimental study of energy harvesting technique to use waste energy in the road. The waste energy in the road is covered a pressure and impact of vehicles on the road, the radiant heat from asphalt pavement, road noise and vibration etc. In this study, an energy harvesting device using piezoelectric element is proposed and various tests are conducted to investigate a characteristic of this device as function of impact loading based on piezoelectric effect behavior. This paper shows the energy harvesting results of the device using domestic piezoelectirc element as a function of impact load size and pavement types.
Comparison of Fuel Consumption Estimation for Passenger Cars
Yoo, In-Kyoon ; Kim, Je-Won ; Lee, Su-Hyeong ; Ko, Kwang-Ho ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 167~175
DOI : 10.7855/IJHE.2011.13.4.167
Evaluation of fuel consumption for the various road condition and vehicle type is necessary to perform the economic analysis of road construction which is important for the efficient design and management of road. Economic analysis of road should consider the social cost which can be divided into agency cost including initial construction expense, maintenance cost, and so on, and user cost consisting of vehicle operating cost, congestion cost, etc. Since vehicle operating cost depends on the traffic volume, fuel consumption that is a major part of vehicle operating cost will change by traffic volume as well. Fuel consumption is significantly affected by vehicle speed and road condition, especially the roughness. Thus, fuel consumption should be evaluated in terms of road condition, which is not currently considered. In this study, the estimation model of fuel consumption for the passenger cars in Korea has been developed by considering the road condition. First, the relationship between vehicle speed and fuel consumption that is used to calculate the vehicle operating cost for investment evaluation of transportation facility and the initial feasibility study of road construction was investigated. Second, with the consideration of road roughness, fuel consumption of the passenger car was measured. From the measurement, it was found that fuel consumption increased by
per 100km driving as the roughness increased by 1m/km. Therefore, it is recommended that for the economic analysis of road design and management, the fuel consumption should be a function of road roughness.
Study of the Effect of the Point-to-Point Speed Enforcement System Using a Comparison-Group Method
Yun, Il-Soo ; Park, Sung-Ho ; Oh, Bong-Sik ; Oh, Young-Tae ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 177~185
DOI : 10.7855/IJHE.2011.13.4.177
In order to reduce traffic accidents at long road sections involving high risks of traffic accidents, including tunnels, bridges or curves, the National Police Agency have decided a tentative installation and operation of an automated point-to-point speed enforcement system based on cameras at January, 2007. The first system was established at the direction to Kangreung of Dunnae Tunnel at December, 2007. Currently, the automated point-to-point speed enforcement system operates at 11 sections including eight sections on expressways and three sections on national highways. However, there have been few researches on the effects of the system upon the reduction of traffic accidents in a scientific way. To this end, this research effort was initiated to evaluate the effect of the automated point-to-point speed enforcement system on traffic safety by comparing the number of traffic accidents before and after the installation of the system using a comparison-group(C-G) method. Three-year-long traffic accident data for the expressways were collected in order to evaluate the system. As a result, the installation of the system was found to reduce traffic accidents by 49.97% in average.
Development of Traffic Safety Behavioral Index on Elementary School Children
Hwang, Dae-Chul ; Choi, Beom-Seok ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 187~198
DOI : 10.7855/IJHE.2011.13.4.187
Researches on children's traffic behavior have only focused on traffic accidents and the number of accidents, and therefore it's been impossible to deal with more broad field of study. In this research we can review the possibility of traffic accidents of children and provide them with traffic education. The goal of this research is to develop a device for measuring possibility of children in terms of traffic behavior. Around 600 elementary students of two schools involved in the pretest with 259 questions and about 3,500 students(junior level 53 questions & senior level 72 questions) involved in practical test. At the result of the research, junior level extracted 4 factors(Lack of behavioral control, Aggressive, Self-regulation, Impulsive Instinct) and 44 questions, and senior level extracted 4 factors(Lack of behavioral control, Depression, Sense-oriented, Aggressive) and 69 questions. We take the gender consideration in separate the groups whether the group has traffic behavioral problem or not. In these series of research, we got the standard score such as junior male student, 63 & female student, 50 and senior male student, 110 & female student, 99.
Analysis of Traffic Crash Severity on Freeway Using Hierarchical Binomial Logistic Model
Mun, Sung-Ra ; Lee, Young-Ihn ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 199~209
DOI : 10.7855/IJHE.2011.13.4.199
In the study of traffic safety, the analysis on factors affecting crash severity and the understanding about their relationship is important to be planning and execute to improve safety of road and traffic facilities. The purpose of this study is to develop a hierarchical binomial logistic model to identify the significant factors affecting fatal injuries and vehicle damages of traffic crashes on freeway. Two models on death and total vehicle damage are developed. The hierarchical structure of response variable is composed of two level, crash-occupant and crash-vehicle. As a result, we have gotten the crash-level random effect from these hierarchical structure as well as the fixed effect of covariates, namely odds ratio. The crash on the main line and in-out section have greater damage than other facilities. Injuries and vehicle damages are severe in case of traffic violations, centerline invasion and speeding. Also, collision crash and fire occurrence is more severe damaged than other crash types. The surrounding environment of surface conditions by climate and visibility conditions by day and night is a significant factor on crash occurrence. On the orher hand, the geometric condition of road isn't.
An Empirical Analysis on Public Transportation Demand and TOD Design Factors in Seoul subway adjacent area
Moon, Young-Il ; Rho, Jeong-Hyun ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 211~220
DOI : 10.7855/IJHE.2011.13.4.211
TOD(Transit Oriented Development) has recently been active, which presents that TOD planning elements should be comprehensively taken into consideration in order to enhance domestic transit ridership by changing environments in rail station areas and an empirical analysis on the type of rail station areas and transportation demand should be a prerequisite for usage of future development planning. This study aims to grasp a variety of TOD of influence factors in Seoul rail station area and to perform analysis to identify relationship between public transportation demand and these TOD design factors. To make it come true, we gathered data with respect to Density, Diversity, and Accessibility as representative TOD planning elements and carried out factorial and regression analysis. Consequently, we drew 7 influence factors base on factorial analysis: Factor 1(Diversity/ -Use Mix(LUM)), Factor 2(Density/development density), Factor 3(Accessibility/public transportation facility supply), Factor 4(Design/street design), Factor 5(Green/access mode (pedestrian, bike), Factor 6(Design/subway size), Factor 7(Accessibility/Public transit operation) As the result of model development by using factorial and regression analysis, positive influence factors on passenger flow in rail station area are Factor 1(Diversity : Land-Use Mix), Factor 3(Accessibility : public transportation facility supply), Factor 2(Density : development density), Factor 5(Design/ access mode) and Factor 6(subway size) Next, negative influence factor on passenger flow in rail station area shows Factor 7(Accessibility/Public transit operation) as the most influential factor. This is because the growth of service interval of linked subway and bus leads to reduced demand.
Terrain Classification for Road Design
Kim, Yong-Seok ; Cho, Won-Bum ; Kim, Jin-Kug ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 221~229
DOI : 10.7855/IJHE.2011.13.4.221
Road design needs to ensure the economic justification and the preservation of nature by adapting road alignment to the natural terrain. Though current road design guideline only defines a flat and a mountainous terrain, classification including rolling terrain should be needed while considering the fact that about 25.8% of our land can be classified as rolling and the road design guideline of developed countries such as United States and Australia has a terrain classification including rolling in order to take a deep consideration on the natural environment. The study attempts to draw a criterion to classify the assumed three individual terrains in a quantitative way by using a index like the undulation of the original ground profile. The study carried out a case study based on a conceptual frame developed in the study as an approach to differentiate each terrain. As a result, the study suggests a criterion in that a flat terrain has less than 40 meters in the difference between the highest and the lowest point of original ground from 40 to 60 meters for rolling terrain, and greater than 60 meters for mountainous respectively.
The Study on the optimized LED module of VMS for saving energy
Kim, Young-Rok ; Lee, Suk-Ki ;
International Journal of Highway Engineering, volume 13, issue 4, 2011, Pages 231~238
DOI : 10.7855/IJHE.2011.13.4.231
Variable message signs(VMS) in use are being displaying with the LED device as the luminous source, and it is a recent trend to be changed from the Lamp type to the Surface-Mount Devices(SMD) type. The LED device leads to get VMS display brightly and clearly, leading to have visibility and legibility better than the existing VMS. However, the lights which display off the road, the unnecessary energy, might have negative effect on ecosystem. This study developed the way of getting the lights be displayed only to drivers without the unnecessary energy and estimated the energy efficiency of the development by the optical testing. As a result, this study showed that the energy consumption of the developed display device appeared to decrease by about 36.1% compared to the existing device. Also the upward and downward angle of the lights changed from an angle of
and from an angle of
, respectively. Therefore, it anticipates that the developed device would benefit highway safety due to an improvement in visibility and legibility compared to the existing VMS and the energy consumption would be less lower than the existing VMS.