• 제목/요약/키워드: Roadways

검색결과 135건 처리시간 0.026초

휘발유 및 환경 담배 연기 관련 벤젠 노출 (Exposure to Benzene Associated with Gasoline and Environmental Tobacco Smoke)

  • 조완근;문경조
    • 한국환경과학회지
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    • 제8권3호
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    • pp.319-323
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    • 1999
  • This study was designed to evaluate the exposure to benzene by residents in neighborhoods near a major roadways, by persons waiting buses, and by drivers and service station attendants while refueling. It was confirmed that the outdoor air benzene concentrations near the major roadways were higher than those further away from the sources. However, neither the indoor air nor breath concentrations were different for two specified residential areas. Smoking was confirmed as an important factor for the indoor air benzene levels. Persons waiting buses, drivers and service station attendants were exposed to elevated benzene levels compared to even the residents in neighborhoods near a major roadways. The mean benzene concentration at bus stop was 2.7 to 6.9 times higher than the mean ambient air concentration. The mean benzene concentrations in the breathing zone of drivers and service station attendants were 95 to 160 and 120 to 202 times higher than the mean ambient air concentrations, respectively.

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Evaluating the performance AASHTOWare's mechanistic-empirical approach for roller-compacted concrete roadways

  • Emin Sengun
    • Computers and Concrete
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    • 제33권4호
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    • pp.445-469
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    • 2024
  • The Federal Highway Administration (FHWA) has recommended the use of AASHTOWare Pavement Mechanistic-Empirical Design (PMED) software for Roller-Compacted Concrete (RCC) pavement design, but specific calibration for RCC is missing. This study investigates the software's capacity to predict the long-term performance of RCC roadways within the framework of conventional concrete pavement calibration. By reanalyzing existing RCC projects in several U.S. states: Colorado, Arkansas, South Carolina, Texas, and Illinois, the study highlights the need for specific calibration tailored to the unique characteristics of RCC. Field observations have emphasized occurrence of early distresses in RCC pavements, particularly transverse-cracking and joint-related issues. Despite data challenges, the AASHTOWare PMED software exhibits notable correlation between its long-term predictions and actual field performance in RCC roadways. This study stresses that RCC applications with insufficient joint spacing and thickness are prone to premature cracking. To enhance the accuracy of RCC pavement design, it is essential to discuss the inclusion of RCC as a dedicated rigid pavement option in AASHTOWare PMED. This becomes particularly crucial when the rising popularity of RCC roadways in the U.S. and Canada is considered. Such an inclusion would solidify RCC as a viable third option alongside Jointed Plain Concrete Pavements (JPCP) and Continuously Reinforced Concrete Pavements (CRCP) for design and deployment of rigid pavements. The research presents a roadmap for future calibration endeavors and advocates for the integration of RCC pavement as a distinct pavement type within the software. This approach holds promise for achieving more precise RCC pavement design and performance predictions.

일반도로 중앙분리대 측 백색 실선 도입 타당성 분석 연구 (Feasibility Analysis for White Pavement Markings in the Roadways with Median Barrier)

  • 김다예;홍경식;이호원
    • 한국도로학회논문집
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    • 제20권3호
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    • pp.75-84
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    • 2018
  • PURPOSES: This study analyzes feasibility for application white pavement markings in the roadways with median barrier. METHODS : By reviewing numerous relevant laws, standards, and operational cases, the white pavement markings' excellence was demonstrated. Driver's behavior was analyzed through a virtual driving experiment using driving simulator and field tests. RESULTS:First, white pavement markings are superior to yellow pavement markings in terms of visibility, economics, and safety. Second, as a result of virtual driving experiment, the color of line in the roadway with median barrier didn't affect the driver's behavior such as the average vehicle speed, the distance bias in the lane and the separation distance from the centerline. Third, field test demonstrated that the driver tended to recognize the median barrier as an obstacle. In addition, the central driving ratio in the lane was increased due to improving the visibility of line at night in case of the white pavement markings. CONCLUSIONS : The application of white pavement markings in the roadways with median barrier can enhance traffic safety by improving the visibility of line at night.

실내시험과 현장암반분류를 이용한 광산갱도의 안정성 해석 (Stability Analysis of Mine Roadway Using Laboratory Tests and In-situ Rock Mass Classification)

  • 김종우;김민식;이동길;박찬;조영도;박삼규
    • 터널과지하공간
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    • 제24권3호
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    • pp.212-223
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    • 2014
  • 본 연구에서는 고심도 금속광산갱도에 대한 안정성 해석을 수행하였다. 이를 위해 수압파쇄법으로 암반의 초기지압을 측정하였고, 현장에서 채취한 암석코어로 수많은 실내물성시험을 실시하여 무결암의 물성 값을 산출하였으며, 현장조사를 통해 GSI, RMR 분류법으로 암반을 분류하였다. 암반분류 결과에 대한 시나리오 분석과 확률론적 평가를 통해 광산 갱도를 최상조건, 평균조건, 최하조건으로 구분하였으며, 각 조건별 탄소성해석을 통해 갱도의 안정성을 평가하였다. 또한, 갱도의 형상과 발파손상대의 영향을 고려한 해석을 통해 갱도의 적절한 규격과 지보패턴을 조사하였는데, 본 광산 갱도의 안정성 제고를 위해서는 갱도의 천반 곡률반경을 감소시키거나 천정부 보강이 필요한 것으로 나타났다.

도로변 난류특성과 교통량에 따른 차량유발 난류강도 정량화: 도로변 풍상/풍하 측에서의 3차원 풍속 동시 측정에 기반 (Quantification of Turbulence Characteristics on the Concentration Distributions of Traffic-related Pollutants Near Roadways)

  • 박용미;한수빈;송한결;이승복;곽경환;김창혁;최원식
    • 대기
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    • 제33권4호
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    • pp.343-354
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    • 2023
  • Turbulence produced on roadways is one of the major factors determining the dilution rates at the initial stage of traffic emissions of air pollutants and, thus, the distribution of air pollutants near the roadways. Field experiments were conducted on Gyeongbu Highway, one of the busiest highways in Korea, for 4~7 days in winter, spring, and summer. Two three-dimensional ultrasonic anemometers were installed on both sides of the highway to estimate turbulence intensities (vertical wind fluctuation and kinetic turbulence energy) induced by the roadway. Roadway-induced turbulence consists of three components: structural road-induced turbulence (S-RIT), thermal road-induced turbulence (T-RIT), and vehicle-induced turbulence (VIT). The contribution of T-RIT to the total RIT was insignificant (less than 10%), and the majority of RIT was S-RIT (by the highway embankment) and VIT. In this study, we propose the empirical relationships of VIT as a function of traffic density and wind speed under free-flow traffic conditions. Although this empirical relationship appears to underestimate the VIT, it can be applied to the air quality models easily because the relationship is simple and only needs readily obtainable input variables (wind speed and traffic information).

IHSDM의 국내도로 적용성 분석 및 도로설계 안전성 평가 시스템의 사용자 요구분석 (Analysis of Applicability of IHSDM into Korea and User Requirements for Development of Road Design Safety Assessment System)

  • 김응철;이동민;최은진;김도훈
    • 대한교통학회지
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    • 제27권4호
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    • pp.155-166
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    • 2009
  • 국내에서의 도로설계 안전성 평가는 도로설계 전문가의 설계도면 검토, 현장방문을 통한 자문자료를 통하여 이루어져왔다. 이러한 설계 안전성 평가는 전문가의 판단을 뒷받침 할 수 있는 객관적인 근거가 부족하다는 문제점과 안전측 편익을 계산하기 위한 수치적인 결과가 부족하다는 문제점이 있다. 본 연구에서는 이러한 문제점을 개선 보완할 수 있는 도로설계 안전성 평가 시스템을 개발하기 위해 IHSDM의 국내도로 적용성 평가, 잠재적 사용자 요구분석을 수행하였다. IHSDM의 사고예측모듈에서 안전성을 평가하기 위해 도로구간별 사고빈도 및 사고율을 산정하는 방법론과 도로의 특성을 반영할 수 있도록 하고 있는 AMF의 개발은 기존의 사고예측모형을 통한 사고예측이나 전문가 판단을 통한 안전성 평가의 한계점을 보완하고 있다. 그러나 이 같은 장점에도 불구하고 국내도로의 IHSDM 적용성 평가 결과 국내도로의 사고를 과대 예측하는 경향을 보여 국내도로의 사고특성을 반영하지 못하는 것으로 나타났다. IHSDM이 반영하지 못하는 대표적 지방부 국내도로 특성으로는 도로변 토지이용도와 미국과는 상이한 지방부 도로의 교통량특성인 것으로 나타났다. 또한, 사용자 요구분석을 통해서는 데이터 입력방식과 도출된 결과를 제시하는 방법의 다양성과 편의성이 확보가 중요시 되는 것으로 분석되었다.

Challenges of Transport Sector in India: A Dyadic Perspective

  • Potluri, Rajasekhara Mouly;Tejaswi, Satagopam Padma
    • The Journal of Asian Finance, Economics and Business
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    • 제5권3호
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    • pp.95-102
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    • 2018
  • The objective of this research is to explore the diverse challenges faced by the customer as well transport providers through the selected modes of transportation of the second most populous country in the world - India. Two separate well-structured questionnaires administered to garner the opinions on different challenges. A random sample of 100 equally selected from the customers of 3 modes of transportation along with 30 transport providers. The collected data was analyzed in Microsoft Excel and R Studio platforms using Percentile Rank Tool and R Programming Language for Chi-square test respectively. Traffic congestion coupled with parking is the major problem in case of roadways while Safety and cleanliness in railways are the first amongst the problems to reckon with. High fares and lack of trained employees are the biggest challenges faced by aviation industry. The research is concentrated only in the states of Andhra Pradesh and Telangana in India with most widely used three modes of transportation viz., Road, Rail and Airways. This research paper is first of its kind which has collected the opinions of both customers as well transport providers on the problems faced. This research proffers information about the challenges faced by the customers which there will be an enormous possibility to review their strategies and plans.

안전한 도로 공사구간 환경 구축에 필요한 기술의 우선순위 선정 (Prioritization of Potential Technology for Establishing a Safe Work Zone Environment)

  • 김진국;양충헌;윤덕근
    • 한국도로학회논문집
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    • 제17권6호
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    • pp.117-126
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    • 2015
  • PURPOSES : This study prioritizes potential technology for establishing a safe work zone environment on roadways. We consider almost all conceivable technologies that enable mitigation of unexpected accidents for both road workers and drivers. METHODS : This study suggests a methodology to set the priority of potential technology for establishing a safe work zone environment by using the analytical hierarchy process (AHP). For this purpose, the AHP structure was first developed. Thereafter, a web-based survey was conducted to collect experts' opinions. Based on the survey results, weights associated with the relevant criteria of the developed structure were estimated. With the consistency index (CI) and consistency ratio (CR), we verified the estimated weights. In addition, a sensitivity analysis was performed to confirm whether the estimated weights were reliable. We finally proposed the priority for potential technology for establishing a safe work zone environment on roadways. RESULTS : In the first level, safety technology has the highest priority, and real-time information delivery for work zone, hazard warning for drivers, and temporal automated operation for traffic facilities were selected in the second level of hierarchy. CONCLUSIONS : The results imply that establishing the priority will be useful to establish a future road map for improving the work environment for road workers and drivers by employing appropriate protection facilities and developing safety systems.