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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 14, Issue 6 - Dec 2012
Volume 14, Issue 5 - Oct 2012
Volume 14, Issue 4 - Aug 2012
Volume 14, Issue 3 - Jun 2012
Volume 14, Issue 2 - Apr 2012
Volume 14, Issue 1 - Feb 2012
Selecting the target year
Development of Viscoelastic Finite Element Analysis Code for Pavement Structures
Lee, Chang-Joon ; Yoo, Pyeong-Jun ; Choi, Ji-Young ; Ohm, Byung-Sik ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 1~9
DOI : 10.7855/IJHE.2012.14.5.001
PURPOSES: A viscoelastic axisymmetric finite element analysis code has been developed for stress analysis of asphalt pavement structures. METHODS: Generalized Maxwell Model (GMM) and 4-node isoparametric element were employed for finite element formulation. The code was developed using
computer program language and named as KICTPAVE. For the verification of the developed code, a structural model of a pavement system was constructed. The structural model was composed of three layers: asphalt layer, crushed stone layer, and soil subgrade. Two types of analysis were considered for the verification: (1)elastic static analysis, (2)viscoelastic time-dependent analysis. For the elastic static analysis, linear elastic material model was assigned to all the layers, and a static load was applied to the structural model. For the viscoelastic time-dependent analysis, GMM and linear elastic material model were assigned to the asphalt layer and all the other layers respectively, and a cyclic loading condition was applied to the structural model. RESULTS: The stresses and deformations from KICTPAVE were compared with those from ABAQUS. The analysis results obtained from the two codes showed good agreement in time-dependent response of the element under the loading area as well as the surface deformation of asphalt layer, and horizontal and vertical stresses along the axisymmetric axis. CONCLUSIONS: The validity of KICTPAVE was confirmed by showing the agreement of the analysis results from the two codes.
Estimation of Performance and Pavement Life using National Highway Pavement Condition Index
Do, Myung-Sik ; Lee, Yong-Jun ; Lim, Kwang-Su ; Kwon, Soo-Ahn ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 11~19
DOI : 10.7855/IJHE.2012.14.5.011
PURPOSES: The new methodology is proposed for estimation of long-term performance and pavement life based on the national highway database in Daejeon area. Furthermore, this study tried to verify the applicability of performance estimation using NHPCI (National Highway Pavement Condition Index) on tendency of pavement deterioration as time goes by under Korean road environments. METHODS: Reliability theories are applied to estimate the mean life and to determine the appropriate distribution using 3 levels of traffic loads (high, medium, low) based on maintenance and rehabilitation history data for 15 years. RESULTS: As a result, Lognormal distribution is suitable for explanation of pavement lifetime in Daejeon area regardless of traffic loads. In addition, we found that the results of mean life and maintenance timing based on NHPCI for the pavement sections of 3 levels of traffic loads are available. CONCLUSIONS: Based on this study, it was found that mean life of high, medium and low levels of traffic loads are about 8.1 years, 12.2 years and 12.7 years, respectively. Higher level of traffic loads shorten the pavement mean life.
Mechanical Performance of Fiber Reinforced Lean Concrete for Subbase of Newly Developed Multi-Functional Composite Pavement System
Jang, Young-Jae ; Park, Cheol-Woo ; Park, Young-Hwan ; Jung, Woo-Tai ; Choi, Sung-Yong ; Yoo, Pyeong-Jun ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 21~29
DOI : 10.7855/IJHE.2012.14.5.021
PURPOSES: This study is to investigate the mechanical performance of the fiber reinforced lean concrete with respect to different types of fibers. METHODS: Increased vehicle weight and other causes from the exposed conditions have accelerated the deteriorations of road pavement. A new multi-functional composite pavement system is being developed recently in order to extend service life and upgrade the pavement. A variety of tests were conducted before and after hardening of the concrete. RESULTS: From the test results, it was found that the use of different types of fibers did not affect the compressive strength development. This might be due to the inherent property of the lean concrete. When steel fibers were used relatively greater flexural strength and flexural fracture toughness were developed. Also addition of fly ash by replacing a part of Portland cement the fracture toughness was slightly increased. CONCLUSIONS: It has been known that the addition of fibers and use of mineral admixture can be positively considered in the development of multi-functional composite pavement system as its required mechanical performance is obtained.
A Study on the Bond-Behavior of Bonded Concrete Overlays
Kim, Young-Kyu ; Lee, Seung-Woo ; Han, Seung-Hwan ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 31~45
DOI : 10.7855/IJHE.2012.14.5.031
PURPOSES: In Korea, rapid maintenance of distressed concrete pavement is required to prevent traffic jam of the highway. Asphalt concrete overlay has been used as a general maintenance method of construction for aged concrete pavement. AC overlay on existing concrete pavements experience various early distresses such as reflection crack, pothole and rutting, due to different physical characteristics between asphalt overlay and existing concrete pavement. Bonded concrete overlay(BCO) is a good alternative since it has advantages that can reduce various distresses during the service life since overlay material has similar properties with existing concrete pavements. Recently, BCO which uses the ultra rapid harding cement has been applied for maintenance of highway. BCO has advantage of structural performance since it does monolithic behave with existing pavement. Therefore, it is important to have a suitable bond strength criteria for securing performance of BCO. Bond strength criteria should be larger than normal tensile stress and horizontal shear stress occurred by traffic and environmental loading at bond interface. Normal tensile stress and horizontal shear stress need to estimated for the establishment of practical bond strength criteria. METHODS: This study aimed to estimate the bond stresses at the interface of BCO using the three dimensional finite element analysis. RESULTS: As a result of this study, major failure mode and maximum bond stress are evaluated through the analysis of normal tensile stress and horizontal shear stress for various traffic and environmental load conditions. CONCLUSIONS: It was known that normal tensile stresses are dominated by environmental loading, and, horizontal shear stresses are dominated by traffic loading. In addition, bond failure occurred by both of normal tensile stresses and horizontal shear stresses; however, normal tensile stresses are predominated over horizontal shear stresses.
Performance Evaluation of Polymer Modified Asphalt Binder with PG Testing Protocols
Yun, Tae-Young ; Ohm, Byung-Sik ; Yoo, Pyeong-Jun ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 47~55
DOI : 10.7855/IJHE.2012.14.5.047
PURPOSES: SUPERPAVE binder grade tests including Multiple Stress Creep and Recovery(MSCR) test are applied to evaluate rheological properties of four polymer modified binders. METHODS: To evaluate grade of four modified binders, PG testing protocols, such as DSR, BBR and MSCR are employed. RESULTS: It is observed that MSCR test shows different performance grades especially on modified binders. Both DMP and EG binder show similar high temperature performance to SBS 5% modified binder. CONCLUSIONS: Binder Grading system in Korea need to be reviewed to properly reflect the performnace of modified binders. The binders modified with DMP and EG can be possible alternatives SBS 5% modified binder considering its performance and cost.
A Experimental Study on Application of KS F 2456 using Shear Wave
An, Ji-Hwan ; Jeon, Sung-Il ; Kwon, Soo-Ahn ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 57~65
DOI : 10.7855/IJHE.2012.14.5.057
PURPOSES: It is important to consider the long-term performance of concrete pavement, because concrete pavement is more exposed to the various environmental conditions than any other concrete structures. One of the several methods to evaluate the long-term performance of concrete during winter is KS F 2456. Relative dynamic modulus of elasticity shows the resistance to freezing and thawing. METHODS: To measure relative dynamic modulus of elasticity, ultra sonic is generally used. But in this study, to measure the relative dynamic modulus of elasticity, both ultra sonic and shear wave were used and then compared each other. RESULTS: The results from the measurement by ultrasonic wave and shear wave were divided into three types. Type 1 : Specimens are good and relative dynamic modulus of elasticity did not decrease until 300 cycle. Type 2 : The relative dynamic modulus of elasticity decreased from the late cycle.(about 150 cycle later) Type 3 : The relative dynamic modulus of elasticity consistently decreased from the beginning. As a result of ANOVA, there is no difference according to measuring method, in type 2 and 3. But there is a difference according to measuring method, in type 1's relative dynamic modulus of elasticity. CONCLUSIONS: It is proved that shear wave can be used to understand the damage tendency of relative freezing and thawing and to measure the relative dynamic modulus of elasticity.
An Analysis on the Effect Factors of the Abrasion Resistance of Interlocking Concrete Block for Roadways
Lee, Min-Kyoung ; Cho, Yoon-Ho ; Lee, Jae-Hoon ; Park, Jun-Young ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 67~74
DOI : 10.7855/IJHE.2012.14.5.067
PURPOSES: In this study the influence factors related to abrasion resistance of interlocking concrete block have been evaluated, and comparisons between various domestic and foreign abrasion test methods was also accomplished. METHODS: The modified rotational cutting method suggested in ASTM C 944 was applied. Surface materials with different types of fine aggregate such as crushed sand, sea sand, and mixture of crushed and sea sand were tested to compare the aggregate effect for abrasion resistance. RESULTS: The different surface mixtures with various W/C ratios, mortar and fly ash ratios have been investigated for functional and economical considerations. CONCLUSIONS: This study had obtained reliable results by changing diamond blade of rotating cutter. Therefore, in order to improve the abrasion resistance of interlocking concrete block for road, a new mix design was proposed.
A Viscoplastic Constitutive Model Based on Overstress Concept with Time-Temperature Superposition Principle
Yun, Tae-Young ; Ohm, Byung-Sik ; Yoo, Pyeong-Jun ; Kim, Yeon-Bok ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 75~83
DOI : 10.7855/IJHE.2012.14.5.075
PURPOSES: Suggestion of asphalt binder constitutive model based on time-temperature superposition principle and overstress concept in order to describe behavior of asphalt binders. METHODS: A series of temperature sweep tests and multiple stress creep and recovery(MSCR) tests are performed to verify the applicability of time-temperature superposition principle(t-Ts) and to develop viscoelastoplastic constitutive equation based on overstress concept. For the tests, temperature sweep tests at various high temperature and various frequency and MSCR test at
are performed. From the temperature sweep tests, dynamic shear modulus mastercurve and time-temperature shift function are built and the shift function and MSCR at
are utilized to determine model coefficients of VBO model. RESULTS: It is observed that the time-temperature shift function built at low strain level of 0.1% is applicable not only to 1.0% strain level temperature sweep test but also maximum 500,00% strain level of MSCR test. As well, the modified VBO model shows perfect prediction on MSCR measured strain at the other temperatures. CONCLUSIONS: The Time-temperature superposition principle stands hold from very low strain level to very high strain level and that the modified VBO model can be applicable for various range of strain and temperature region to predict elastic, viscoelastic, and viscoplastic strain of asphalt binders.
Laboratory Testing of Material Properties of Asphalt Binder Containing Wasted Vinyl
Lee, Kang-Hun ; Kim, Young-Chin ; Kim, Byeong-Jun ; Lim, Jin-Sun ; Jeong, Jin-Hoon ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 85~91
DOI : 10.7855/IJHE.2012.14.5.085
PURPOSES: In this study, various laboratory tests were performed to investigate the suitability of wasted vinyl as a modifier of asphalt binder. METHODS: Based on the ASTM specification, variations in material properties of asphalt binder such as penetration, flash point, softening point, ductility, penetration index (PI), and performance grade (PG) with vinyl content were tested and analyzed. RESULTS: Lavoratory tests revealed that penetration and ductility of the asphalt binder increased with the vinyl content. The flash point, softening point, and PI decreased, and PG changed from 64-22 to 70-22 with increase of the vinyl content. CONCLUSIONS: Wasted vinyl modified the material properties of the asphalt binder. However, the asphalt binder with vinyl content over 6.0% was unsuitable as a pavement material.
Comparison of Alkali-Silica Reactivity for Mortar Bar and Concrete Prism Specimens Using Crushed Aggregates in Korea
Kim, Seong-Kwon ; Yun, Kyong-Ku ; Hur, In ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 93~99
DOI : 10.7855/IJHE.2012.14.5.093
PURPOSES: The purpose of this study is to compare the alkali-silica reactivity for mortar bar and concrete prism specimens using crushed aggregates of 5 types in Korea. And the alkali-silica reactivity for those aggregates are measured by chemical test method. METHODS: The alkali-silica reactivity for those aggregates was measured by chemical test method of KS F 2545, mortar-bar test of KS F 2546, accelerated mortar-bar test method of ASTM C 1260 and concrete prism test method of ASTM C 1293, relatively. RESULTS: The alkali-silica reactivity for those aggregates was verified by chemical test of KS F 2546 and accelerated mortar-bar test of ASTM C 1260. However, it was not by mortar-bar test of KS F 2546 and concrete prism test of ASTM C 1293. CONCLUSIONS: The above results showed that relationship among the four test methods were very low. The results from 3 types of test methods using cement-aggregate combinations appeared to be different. Because the environmental conditions of test methods for measuring the alkali-silica reactivity such as equivalent alkali content(external source), humidity, temperature, and times were different though the aggregates were same. Moreover, alkali-silica reactivity showed the biggest impact when alkalis were supplied form outside and exposed to environmental conditions. The accelerated mortar-bar test method seems to be most appropriate test method for concrete structures exposed to alkali environment.
Prediction Models for the Severity of Traffic Accidents on Expressway On- and Off-Ramps
Yun, Il-Soo ; Park, Sung-Ho ; Yoon, Jung-Eun ; Choi, Jin-Hyung ; Han, Eum ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 101~111
DOI : 10.7855/IJHE.2012.14.5.101
PURPOSES: Because expressway ramps are very complex segments where diverse roadway design elements dynamically change within relatively short length, drivers on ramps are required to drive their cars carefully for safety. Especially, ramps on expressways are designed to guarantee driving at high speed so that the risk and severity of traffic accidents on expressway ramps may be higher and more deadly than other facilities on expressways. Safe deceleration maneuvers are required on off-ramps, whereas safe acceleration maneuvers are necessary on onramps. This difference in required maneuvers may contribute to dissimilar patterns and severity of traffic accidents by ramp types. Therefore, this study was aimed at developing prediction models of the severity of traffic accidents on expressway on- and off-ramps separately in order to consider dissimilar patterns and severity of traffic accidents according to types of ramps. METHODS: Four-year-long traffic accident data between 2007 and 2010 were utilized to distinguish contributing design elements in conjunction with AADT and ramp length. The prediction models were built using the negative binomial regression model consisting of the severity of traffic accident as a dependent variable and contributing design elements as in independent variables. RESULTS: The developed regression models were evaluated using the traffic accident data of the ramps which was not used in building the models by comparing actual and estimated severity of traffic accidents. Conclusively, the average prediction error rates of on-ramps and offramps were 30.5% and 30.8% respectively. CONCLUSIONS: The prediction models for the severity of traffic accidents on expressway on- and off-ramps will be useful in enhancing the safety on expressway ramps as well as developing design guidelines for expressway ramps.
Analysis of CO
Emission Sensitivity in Roadways
Lee, Yoon-Seok ; Oh, Heung-Un ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 113~122
DOI : 10.7855/IJHE.2012.14.5.113
PURPOSES: The sensitivity of
emissions per vehicle by a various speeds is compared according to the type of roads. METHODS: The methodology of the study are as follows: First, the sensitivity of
emissions per vehicle are analyzed by averaged daily travel speeds. Second, the sensitivity of
emissions per vehicle are analyzed by averaged hourly travel speed. Third, the sensitivity of
emissions per vehicle are analyzed by sectional travel speeds. RESULTS: The sensitivity that on Saturday in a week, at peak times in a day and in close location from Seoul was higher than in other situations. CONCLUSIONS: From this study, we may conclude that
emissions per vehicle at low speeds are generally more sensitive.
Development of Disaster Risk Analysis System for Environment Friendly Road
Song, Min-Tae ; Kang, Ho-Geun ; Kim, Heung-Rae ; Lee, Tae-Ock ; Lee, Han-Joo ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 123~132
DOI : 10.7855/IJHE.2012.14.5.123
PURPOSES: This study is to investigate the consideration which relates with a disaster from route alignment process and proposed the method it will be able to evaluate a disaster danger fixed quantity. METHODS: Use the landslide disaster probabilistic map of GIS based and in about landslide occurrence of the route alignment at the time of neighboring area after evaluating a risk fixed quantity, it compared LCC expense in about each alternative route. It developed the system it will be able to analyze a LCC and a disaster risk in about the alternative route. In order to verify a risk analytical algorithm and the system which are developed it selected national road 59 lines on the demonstrative route and it analyzed a disaster risk. RESULTS: Demonstrative route not only the disaster risk to be it will be able to compare a disaster risk fixed quantity like the economical efficiency degree in compliance with LCC expense productions it compared and there being the designer will be able to decide the alternative route, it confirmed. CONCLUSIONS: Roads can be designed by considering occurs repeatedly landslides and debris flow caused by disasters in advance and expect to be able to effect that can reduce the overall cost to recover losses caused by the disaster, and temporally loss is expected.
Traffic Crash Prediction Models for Expressway Ramps
Choi, Yoon-Hwan ; Oh, Young-Tae ; Choi, Kee-Choo ; Lee, Choul-Ki ; Yun, Il-Soo ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 133~143
DOI : 10.7855/IJHE.2012.14.5.133
PURPOSES: Using the collected data for crash, traffic volume, and design elements on ramps between 2007 and 2009, this research effort was initiated to develop traffic crash prediction models for expressway ramps. METHODS: Three negative binomial regression models and three zero-inflated negative binomial regression models were developed for individual ramp types, including direct, semi-direct and loop, respectively. For validating the developed models, authors compared the estimated crash frequencies with actual crash frequencies of twelve randomly selected interchanges, the ramps of which have not been used for model developing. RESULTS: The results show that the negative binomial regression models for direct, semi-direct and loop ramps showed 60.3%, 63.8% and 48.7% error rates on average whereas the zero-inflated negative binomial regression models showed 82.1%, 120.4% and 57.3%, respectively. CONCLUSIONS: Conclusively, the negative binomial regression models worked better in traffic crash prediction than the zero-inflated negative binomial regression models for estimating the frequency of traffic accidents on expressway ramps.
Evaluation of Left-Turn Passages for Bicycle Traffic in Mixed Traffic Stream at Signalized Intersections
Joo, Shin-Hye ; Oh, Cheol ; Lee, Sang-Soo ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 145~155
DOI : 10.7855/IJHE.2012.14.5.145
PURPOSES: This study proposes a novel method based on microscopic simulation models to evaluate bicycle passing ways in mixed traffic flow conditions at signalized intersections. METHODS: Both operational efficiency and safety are taken into consideration in the evaluation. A widely used performance measure, delay, is used for evaluating the operational efficiency. Regarding the safety evaluation, surrogate safety measures (SSM) to represent traffic conflicts and the level of crash severity, DeltaS and Max.DeltaV, are applied in the proposed method. RESULTS: Extensive simulations and statistical tests show that an integrated bike-box way is identified as the best in terms of operational efficiency and safety. CONCLUSIONS: The proposed method and outcomes of this study will be valuable for bicycle traffic operations and facility design.
Evaluation for Operational Efficiency of Road Management Equipment using Analytical Hierarchy Process
Yang, Choong-Heon ; Kim, In-Su ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 157~164
DOI : 10.7855/IJHE.2012.14.5.157
PURPOSES: Regional offices of the Ministry of Land, Transport and Maritime Affairs use a computerized system called KAMIS so as to manage road equipment systematically. Road agencies can record number of operating days by equipment, actual working hours, accumulated operating hours (or distance) by equipment, and operating cost. However, KAMIS does not provide critical information, although it is strongly related to efficient road management equipment operation. In other words, road agencies do not know whether they have sufficient equipment to handle their actual work. METHODS: Therefore, this study suggests a methodology to evaluate for operational efficiency of road management equipment using analytical hierarchy process(AHP). First of all, estimated weights related criteria can be produced by AHP, and then use operational history by pieces of equipment. RESULTS: Results show that importance of management work can differ from weather conditions through five areas. CONCLUSIONS: Commonly, this results can imply to help save money for the purchase and maintenance of road management equipment, and they would improve the functional performance of KAMIS.
A Study on the Significance and Relationship Drunken Drivers Characteristics Using Virtual Reality Scenario
Kim, Myung-Soo ; Park, Sang-Jin ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 165~177
DOI : 10.7855/IJHE.2012.14.5.165
PURPOSES: The number of traffic accidents in 2010 was 226,978 in Korea, a high percentage of which up to 12.61% was due to drunk driving. As it is expected that the number of traffic accidents will increase because of the drastic increase of the number of vehicle registrations and the prevalent drinking cultures, it is necessary to understand the driving characteristics of drunken drivers to lower the increasing rate. METHODS: This study, therefore, comparatively analyzes the two groups - one group before drinking and the other after drinking - based on the graph, and implements the correlation in each scenario(1,2,3). scenario 1. appearance of jaywalkers; scenario 2. appearance of an illegal left-turning car; and scenario 3. appearance of a vehicle and a person as obstacles to the driver after an accident. RESULTS: The comparative analysis of speed shows that the group after drinking was 50km/h faster than the group before drinking in Scenario 1, 20km/h in Scenario 2, and 15km/h in Scenario 3 respectively. In the comparative analysis of acceleration, the average level of the group after drinking was 0.15 higher than that of the group before drinking in Scenario 1, 0.30 in Scenario 2, and 0.15 in Scenario 3. In the comparative analysis of deceleration, the average level of the group after drinking was about 0.4 lower than that of the group before drinking in Scenario 1, 0.35 in Scenario 2, and 0.2 in Scenario 3 respectively. In the comparative analyses, the item of speed, acceleration and deceleration was of significance for each group in Scenarios. CONCLUSIONS: The comparative analysis demonstrated that there is a difference between the group before drinking and the group after drinking. In the analysis of correlation in each group, it was proved that the drunken group was of significance.
Overloading Control Effectiveness of Overweight Enforcement System using High-Speed Weigh-In-Motion
Kwon, Soon-Min ; Jung, Young-Yoon ; Lee, Kyung-Bae ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 179~188
DOI : 10.7855/IJHE.2012.14.5.179
PURPOSES: The aim of this study is to analyze overloading control effectiveness of enforcing overweighted vehicles using HS-WIM (High-Speed Weigh-in-Motion) at main lane of expressway. METHODS: To analyze the weight distribution statistically, HS-WIM system should has an appropriate weighing accuracy. Thus, the weighing accuracy of the two HS-WIM systems was estimated by applying European specifications and ASTM (American Standards for Testing and Materials) for WIM in this study. Based on the results of accuracy test, overweight enforcement system has been operated at main lanes of two expressway routes in order to provide weight informations of overweighted vehicle in real time for enforcement squad. To evaluate the overloading control effectiveness with enforcement, traffic volume and axle loads of trucks for two months at the right after beginning of the enforcement were compared with data set for same periods before the enforcement. RESULTS: As the results of weighing accuracy test, both WIM systems were accepted to the most precise type that can be useful to applicate not only statistical purpose but enforcing on overweight vehicles directly. After the enforcement, the rate of overweighted trucks that weighed over enforcement limits had been decreased by 27% compared with the rate before the enforcement. Especially, the rate of overweighted trucks that weighed over 48 tons had been decreased by 91%. On the other hand, in counterpoint to decrease of the overweighted vehicle, the rate of trucks that weighed under enforcement limits had been increased by 7%. CONCLUSIONS: From the results, it is quite clear that overloading has been controlled since the beginning of the enforcement.
Methodology for Determining Functional Forms in Developing Statistical Collision Models
Baek, Jong-Dae ; Hummer, Joseph ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 189~199
DOI : 10.7855/IJHE.2012.14.5.189
PURPOSES: The purpose of this study is to propose a new methodology for developing statistical collision models and to show the validation results of the methodology. METHODS: A new modeling method of introducing variables into the model one by one in a multiplicative form is suggested. A method for choosing explanatory variables to be introduced into the model is explained. A method for determining functional forms for each explanatory variable is introduced as well as a parameter estimating procedure. A model selection method is also dealt with. Finally, the validation results is provided to demonstrate the efficacy of the final models developed using the method suggested in this study. RESULTS: According to the results of the validation for the total and injury collisions, the predictive powers of the models developed using the method suggested in this study were better than those of generalized linear models for the same data. CONCLUSIONS: Using the methodology suggested in this study, we could develop better statistical collision models having better predictive powers. This was because the methodology enabled us to find the relationships between dependant variable and each explanatory variable individually and to find the functional forms for the relationships which can be more likely non-linear.
Noise Evaluation of the Rumble Strips Constructed at Tall Gate of Highway
Lee, Jae-Jun ; Mun, Sung-Ho ; An, Deok-Soon ; Kwon, Soo-Ahn ;
International Journal of Highway Engineering, volume 14, issue 5, 2012, Pages 201~206
DOI : 10.7855/IJHE.2012.14.5.201
PURPOSES: This study evaluated a measuring technique for tire-pavement interaction noise that uses a noble close proximity (NCPX) method as well as for noise level measured inside of a car (e.g., Inside Noise Level) in term of rumble strips constructed at a tall gate. METHODS: According to the measurements of NCPX and inside noise level (INL), 1/3 octave band frequency analysis and overall noise level calculation were conducted in order to evaluate noise levels of NCPX and INL, depending on types of rumble strips. RESULTS: The tested sections of general concrete pavement surface and two different types of rumble strips were evaluated, using 1/3 octave band frequency analysis and overall noise level. From the analyzed results, it can be concluded that rumble strips generate a relatively huge noise levels when compared to the concrete pavement surface. CONCLUSIONS: Noting that above 3 dBA different noise levels can let drivers know that they are getting close to toll gate; therefore, they should apply their brakes. Thus, the noise levels of rumble strips are required to be reduced, based on considering the neighbors living near toll gates.