• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.5
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• pp.253-263
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• 2021

Traffic data collected using advanced equipment are highly valuable for traffic planning and efficient road operation. However, there is a problem regarding the reliability of the analysis results due to equipment defects, errors in the data aggregation process, and missing data. Unlike other detectors installed for each vehicle lane, radar detectors can yield different error types because they detect all traffic volume in multilane two-way roads via a single installation external to the roadway. For the traffic data of a radar detector to be representative of reliable data, the error factors of the radar detector must be analyzed. This study presents a field survey of variables that may cause errors in traffic volume collection by targeting the points where radar detectors are installed. Video traffic data are used to determine the errors in traffic measured by a radar detector. This study establishes three types of radar detector traffic errors, i.e., artificial, mechanical, and complex errors. Among these types, it is difficult to determine the cause of the errors due to several complex factors. To solve this problem, this study developed a radar detector traffic volume error analysis model using a multiple linear regression model. The results indicate that the characteristics of the detector, road facilities, geometry, and other traffic environment factors affect errors in traffic volume detection.

• Journal of Environmental Impact Assessment
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• v.17 no.4
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• pp.213-224
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• 2008

Since 1970's rapid urbanization and economic growth, the population was highly increased and residential type was changed from single detached house to high density and high-rise apartment. Recently more high-rise residential building generates more traffic volumes and it makes spatial concentration. The highly traffic volumed road and high residential building was constructed nearby, it occurs noise problem. The purpose of this study is comparing the performance of three type noise barrier between noise source and receiver using a noise map simulation. Three types were composed as road side planting trees, building side planting trees and noise barrier wall. Planting trees is less effective than noise barrier wall as a noise barrier. And they are all effective under 3 stories than over 5 stories, especially noise barrier function can't work over 5 stories.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.5
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• pp.407-414
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• 2007

Even Korea is big country of automobile, the occurrence of traffic accident is in last place in 29 OECD countries. If it is evaluated by assessment guide of investment over the development project of public-traffic facilities, it was shown that the direct economical loss was fairly great. In this study, in order to minimize the traffic accidents occurring at curve area of road, it was tried to establish the standard of non-passing distance. The close-range photogrammetry was used and three dimensional modeling was fulfilled. Currently, this paper was focused on presenting the standard of road design with analyzing the internal and external standard of non-passing distance.

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.3
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• pp.62-68
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• 2015

As a preparation of a design standard regarding road facilities, such as cantilever columns for traffic lights, street lights on highways is proposed. Currently these minor structures are designed based on guidelines which are mixed with multiple old foreign specifications without any criteria in terms of safety and economy, which could lead irregular safeties and the loss of national properties. In the considered two cases for effective projected area, it is found that following efficient way of design without critical analyses could make significant errors and miscalculations. Therefore, a fundamental research on the minor structures is urgently needed.

• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.41-47
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• 2005

Traffic data such as traffic volume, speed, and vehicle Class are very important basic data for the plan and design of highway. Based on traffic data, the future service level of a specific highway and geometry of newly constructed or expended road is predicted and determined. The Ministry of Construction & Transportation has simultaneously surveyed coverage count and permanent count at highways since 1985. Traffic volume survey sections were determined at jointed nodes of highways and jointed nodes of highways and other roads such as freeway and local highway. Volume survey was performed at these sections. The premise to decide these sections is assumed that links between jointed nodes of main highways exhibit similar traffic characteristics. Recently, due to the change of highway geometries such as construction of detour road and installations of traffic facilities such as installation of media, traffic characteristics of the existing traffic volume survey sections was changed. To reflect these changes, traffic characteristics at homogeneous road sections was widely evaluated and analyzed. Using Genetic Algorithms, a model was developed for the evaluation of traffic characteristics at homogeneous road sections. Traffic volume survey sections were then determined through the application of the developed model for current traffic system.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.199-209
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• 2011

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.

• International Journal of Highway Engineering
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• v.19 no.5
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• pp.163-171
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• 2017

PURPOSES : Traffic safety facilities are used to prevent traffic accidents before they occur by providing drivers with information on traffic situations and the geometric design of roads. However, some facilities not defined in guidelines do not meet installation criteria, yet are being installed and used in order to increase efficiency in traffic flow and prevent traffic accidents in a specific expressway zone. In this study, we have evaluated the effect of delineation system which are not defined in the guideline criteria. METHODS : Different virtual scenarios were created for roads using expressway median barrier chevron signs, with a driving simulator used to evaluate the installation and operational effect of such signs. Ten experiments were performed with left- and right-curved roads at curve radius intervals of 500 m, from 500 m to 2,500 m. RESULTS : For sections with a curve radius of more than 1,500 m, drivers had a clear tendency toward stable driving regardless of delineation system. When a chevron sign is installed on a protection fence in the road curving left, an expanded installation is recommended up to the section with a curve radius of 1,000 m. According to the analysis results for the RHB (Relative High Beta spectrum), driving concentration also improved up to a curve radius of 1,000 m. CONCLUSIONS :The experiment result indicates the extent of biasing within a lane and the manipulation amount of steering handle, were analyzed and found to be affected by curve radius and road alignment regardless of delineation system.

• The magazine of the Korean Society for Advanced Composite Structures
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• v.1 no.3
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• pp.43-45
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• 2010

• Journal of Korean Society of Transportation
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• v.8 no.2
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• pp.7-25
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• 1990

In road traffic, road circumstances, vehicle, and driver are closely related each other. When road facilities are established in road planning, only road structure has been considered. However, relatively little work has been done regarding the relation between road circumstances and human with respect to a driver. This dissertation focuses on analysis of driver's visual characteristics to improve road circumstances. In this study, driver's visual characteristics are measured with eye-mark recorder and analyzed statistically. This study includes that visual characteristics, visual range, visual time, distribution of fixation duration, and visual moving angle with respect to road circumstances are established qualitatively and quantitatively by driving testing vehicle on streets, roads and high-ways. The main features of this study are : The driver's visual ranges are different over 10% depending on lane in multi-lanes. The visual range on two-lanes is more than twice as big as that on multi-lanes at 85% of whole vision. The right and left visual ranges by as big as that on multi-lanes at 85% of whole vision. The right and left visual ranges by as big as that on multi-lanes at 85% of whole vision. The right and left visual ranges by as big as that on multi-lanes at 85% of whole vision. The right and left visual ranges by speed are $34^{\circ}$ for 30-50km/hr, $28^{\circ}$ for 50-70km/hr, $22^{\circ}$ for 70-90km/hr and 16^{\circ} for over 90km/hr at 95% of visual rate. Accordingly, increasing speed results in narrow visual range.

• Journal of Korean Society of Transportation
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• v.33 no.3
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• pp.276-283
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• 2015

Pedestrians have been exposed to dangerous traffic environments, in which walking spaces in a city decrease without improved facilities even though cars increase. Such poor walking environments are deadly dangerous to the vulnerable as well as the non-vulnerable. This study analyzed the road facilities use characteristics according to a type of vulnerability in order to improve traffic safety and walking environment for vulnerable pedestrians. This study surveyed the vulnerable in terms of issues that they encountered on existing walkways and conducted the analytic hierarchy process (AHP), which took all quantitative and qualitative variables into account. The results of Level-3 analysis were showed that the elderly and the disabled were partially similar; both felt most inconvenient at enter-exit sections, steep walkway and bad paved walkway. Unlike those results, people with children and/or infants answered that overpass or underpass walkways without lifting facilities were most inconvenient walking environments.