• 한국도로학회논문집
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• 제19권6호
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• pp.165-173
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• 2017

PURPOSES : The current practice in car headlight visibility performance evaluation is based on the luminous intensity and illuminance of headlight. Such practice can be inappropriate from a visibility point of view where visibility indicates abilities to perceive an object ahead on the road. This study aimed at evaluating the appropriateness of current headlight evaluation method. METHODS : This study measured the luminance of object and road surface at unlit roadways. The variables were measured by vehicle type and by headlight lamp type. Based on the measurements, the distance where drivers can perceive an object ahead was calculated and then compared against such distance obtained by conventional visibility performance evaluation. RESULTS : The evaluation method based on illuminance of headlight is not appropriate when viewed from the visibility concept that is based on object-perceivable distance. Further, the results indicated a shorter object-perceiving distance even when road surface luminance is higher, thereby suggesting that illuminance of headlight and luminance of road surface are not the representative indices of nighttime visibility. CONCLUSIONS : Considering that this study utilized limited vehicle types and that road surface (background) luminance can vary depending on the characteristics of the given road surface, it would likely go too far to argue that this study's visibility performance evaluation results can get generalized to other conditions. Regardless, there is little doubt that the current performance evaluation criterion which is based on illuminance, is unreasonable. There should be future endeavors on the current subject which will need to explore study conditions further, under which more experiments should be conducted and effective methodologies developed for evaluating automotive headlight visibility performance. Needs are recognized particularly in the development of headlight visibility performance evaluation methodology which will take into account road surface (background) luminance and luminance contrast from various perspectives as the former indicates the driver's perception of the front road alignment and the latter being indicative of object perception performance.

• 한국도로학회논문집
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• 제17권5호
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• pp.57-66
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• 2015

PURPOSES: Nighttime driving is very different from daytime driving because drivers must obtain nighttime sight-distances based on road lights and headlights. Unfortunately, nighttime driving conditions in Korea are far from ideal due to poor lighting and an insufficient number of road lights and inadequate operation and maintenance of delineators. This study is conducted to develop new standards for nighttime road visibility based on experiments of driver perception for nighttime visibility conditions. METHODS : In the study, perception level and satisfaction of nighttime visibility were investigated. A total of 60 drivers participated, including 34 older drivers and 31 young drivers. To evaluate driver perceptions of nighttime road visibility, fuzzy set theory was used because the conventional analysis methods for driver perception are limited in effectiveness for considering the characteristics of perception which are subjective and vague, and are generally expressed in terms of linguistic terminologies rather than numerical parameters. RESULTS : This study found that levels of nighttime visibility, as perceived by drivers, are remarkably similar to their satisfactions in different nighttime driving conditions with a log-function relationship. Older drivers evaluated unambiguously degree of nighttime visibility but evaluations by young drivers regarding it were unclear. CONCLUSIONS : A minimum value of brightness on roads was established as YUX 30, based on final analyzed results. In other words, road lights should be installed and operated to obtain more than YUX 30 brightness for the safety and comfort of nighttime driving.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권9호
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• pp.4419-4441
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• 2016

A cause of vehicle accidents is the reduced visibility due to bad weather conditions such as fog. Therefore, an onboard vision system should take visibility detection into account. In this paper, we propose a simple and effective approach for measuring the visibility distance using a single camera placed onboard a moving vehicle. The proposed algorithm is controlled by a few parameters and mainly includes camera parameter estimation, region of interest (ROI) estimation and visibility computation. Thanks to the ROI extraction, the position of the inflection point may be measured in practice. Thus, combined with the estimated camera parameters, the visibility distance of the input foggy image can be computed with a single camera and just the presence of road and sky in the scene. To assess the accuracy of the proposed approach, a reference target based visibility detection method is also introduced. The comparative study and quantitative evaluation show that the proposed method can obtain good visibility detection results with relatively fast speed.

• 조명전기설비학회논문지
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• 제21권6호
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• pp.1-7
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• 2007

본 논문에서는 도로 조명용 광원으로 쓰이는 메탈핼라이드램프, 고압나트륨램프, PLS의 세 가지 광원에 대해 안개 발생시 시인성을 평가하기 위해 특정한 인공 안개 조건하에서 각 광원들에 대한 피시험자들의 평가를 분석하여 명소시에는 고압나트륨램프가 시인성이 좋고 암소시에는 PLS가 시인성이 좋다는 결과를 얻었으며 이 결과는 앞으로의 도로 조명용 광원의 선택에 있어서 도움을 줄 수 있을 것으로 기대된다.

• 한국조경학회지
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• 제25권2호
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• pp.31-42
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• 1997

Visibility has been used for Visual Impact Assessment and Buildingheight Control. The purpose of this study is to elaborate visibility analysis technique in GIS, and to design a visual information system baed on this technique for diverse application. The results of this study are as follows : 1) By classifying visibility analysis techniques into two groups, Each one's merits and demerits were investigated. Practically GIS visibility analysis by DTM model using contour map and investigating it by means of site-observation can be the most effective method. 2) A visibility analysis techniquwe for V.I.A. and B.H.C. was presented by studying GIS visibility analysis by means of DTM model using contour map. There were 5 problems. 3) Adequate analysis techniques were presented according to the landscape factor-road, ship-route, port, mountain, etc. 4) Viewing distance from road and ship-route in visual corridor, landma가 visibility and distance, the angle of incidence and invisible region's depth are helpful for land scape management or land use planning.

• 한국도로학회논문집
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• 제18권1호
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• pp.131-141
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• 2016

PURPOSES : While road networks are becoming increasingly complex, traffic signs are being indiscriminately installed and operated, which makes drivers who depend on traffic signs to reach their destination confused and unable to understand road information efficiently. In order to promptly and exactly guide road users to their destinations, traffic signs should be able to satisfy the functions of connectivity, visibility, and location suitability. However, the results of a site survey shows that most of the traffic signs currently installed in the Jeollanam-do Province do not satisfy these functions. METHODS : This study analyzed the problems of traffic signs after an actual site survey and focused on a total on 9,353 traffic signs and 70 road routes in Jeollanam-do Province. RESULTS : This study analyzed the problems of traffic signs based on their required functions (connectivity, visibility, suitability) and suggested improvements by establishing a guide system that considered the problems found in the study. CONCLUSIONS : The guide system can be utilized as a basic material that provides efficient road information for future installation and maintenance of traffic signs in Jeollanam-do Province.

• 한국산학기술학회논문지
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• 제14권1호
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• pp.385-392
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• 2013

안개로 인한 대형교통사고를 예방하기 위한 안개경고시스템의 핵심요소는 시정을 측정하는 장치이며, 최근 고가의 안개센서 보다 인간의 시정감각과 유사하면서도 저렴하고 정확한 시정측정장치에 대한 필요성이 증대되고 있다. 본 논문은 도로의 CCTV 카메라를 이용하여 시정을 측정하기 위해 개발된 도로시정측정시스템(RVMS)의 성능 평가 방법 및 결과를 제시하고, 고속도로 등 도로 적용에 따른 경제성과 활용방안을 제시한다. 성능평가는 여주시험도로에 전용 CCTV 카메라, 안개센서, 목측을 위한 시정표지를 설치하고 시험운영결과를 DVR에 기록하여, 특정 안개발생 시간대에 대해 RVMS와 안개센서 결과를 목측결과와 비교분석하였다. 실험결과, 목측을 기준으로 RVMS가 안개센서 대비 높은 측정안정성과 정확성을 가진 것으로 분석되었다. 또한, 본 논문에서는 RVMS가 기존 안개센서 대비 높은 경제성을 가지고 있음을 제시하고 RVMS의 다양한 활용방안을 제시한다. 높은 성능과 경제성을 가진 RVMS의 적절한 활용은 안개발생시 도로 이용자의 교통사고 예방뿐만 아니라 광역 시정정보 수집 및 활용에 획기적인 계기를 마련할 것으로 기대된다.

• 스마트미디어저널
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• 제10권4호
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• pp.63-70
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• 2021

도로 위 공공 정보를 안내하는 표지판은 짧은 시간 내에 의사결정을 내릴 수 있도록 도와야 하므로 해당 지점에서 적합한 정보를 효과적으로 표현할 수 있어야 한다. 현재 법령에 의해 개정된 도로표지규칙은 도로명 주소를 기반으로 하려 기존의 도로표지판과 비교할 때 정보의 종류, 표현 방법, 표현 비중 등에서 크게 달라진 모습을 보여주고 있다. 본 연구는 도로명을 기준으로 달라진 개정된 도로표지판이 실제 지각-인지-이해-투영의 인지적인 관점에서 효과적인지를 분석하고 실제 주행하는 환경과 적합한 정보를 제공하고 있는지 검토하였다. 분석한 정보를 기반으로 개선된 디자인을 제시하고, 기존의 도로명 위주의 표지판과 비교하여 시인성 정도를 평가하는 실험을 진행하고 표지판 내용의 적합성에 대한 정성적 조사를 진행하였다. 이를 통해 보다 적합한 주행 정보와 직관적인 시인성을 높이는 방안을 검토할 수 있을 것으로 기대한다.

• 조명전기설비학회논문지
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• 제25권4호
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• pp.1-6
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• 2011

The elder population with 65 years old or more in Korea has been entered into an aging society as 9.1[%] in 2005 to 14.3[%] in 2018. The elder population in 2026 will be expected to 20.8[%] with the rapid aging society. In this study, there has been conducted a study on development of headlamp for elder friendly vehicle in order to ffrom two different groups, one group for elder with over 65 ages, the other group for compared ages(20 ages, 30~50 ages). Glare test and forward visibility test were performed on wet and dry road conditions. As the result of these tests, it showed to prefer headlamp installed partially yellow coated bulb, which gives warm feeling on dry road condition. Forward visibility of headlamp which developed to fit on wet road condition is similar to existing HID headlamp. Glare was evaluated less than halogen and HID headlamp. However, it need to more improve glare and forward visibility performance of headlamp for old drivers.

• 대한공간정보학회지
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• 제22권4호
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• pp.107-115
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• 2014

야간도로 노면 밝기는 운전자가 도로 상 장애물을 인지하고 안전하게 운행하는데 있어 매우 중요한 요소이다. 본 연구에서는 정량적인 야간도로 시인성을 평가에 필요한 야간 도로 노면 영상정보 수집 및 처리용 모바일 체계를 제시하였다. 야간 도로 노면에서 수집되는 영상정보를 효율적으로 변환하고 야간도로 시인성에 대한 공간적인 분포를 파악할 수 있는 선형자료를 구축하였다. 이를 위해 저전력 컴퓨팅기술, 개방형 영상처리 기술, GPU 기반 가속 기술 및 도큐멘트데이터베이스 기술 등을 적용하였고 RGB영상으로부터 YUV색상체계로 변환하고 밝기에 해당하는 요소만 추출하여 공간정보와 통합하였다. 그 결과 고성능 안드로이드 단말기를 이용하여 도로밝기 자료를 취득하고 제안한 프로토타입으로 야간도로 시인성에 대한 공간적인 평가를 위한 자료 구축의 공간적 분포를 파악할 수 있었다.