• Title/Summary/Keyword: Road environment

Search Result 1,775, Processing Time 0.03 seconds

A CFD Study of Roadside Barrier Impact on the Dispersion of Road Air Pollution

  • Jeong, Sang Jin
    • Asian Journal of Atmospheric Environment
    • /
    • v.9 no.1
    • /
    • pp.22-30
    • /
    • 2015
  • This study evaluated road shape and roadside barrier impact on near-road air pollution dispersion using FLUENT computational fluid dynamics (CFD) model. Simulated road shapes are three types, namely at-grade, depressed, and filled road. The realizable k-${\varepsilon}$ model in FLUENT CFD code was used to simulate the flow and dispersion around road. The selected concentration profile results were compared with the wind tunnel experiments. The overall concentration profile results show good agreement with the wind tunnel results. The results showed that noise barriers, which positioned around the at-grade road, decrease the horizontal impact distance (In this study, the impact distance was defined as the distance from road surface origin coordinate to the position whose mass fraction is 0.1.) lower 0.33~0.65 times and change the vertical air pollution impact distance larger 2.0~2.27 times than those of no barrier case. In case of filled road, noise barriers decrease the horizontal impact distance lower 0.24~0.65 times and change the vertical air pollution impact distance larger 3.33~3.55 times than those of no barrier case. The depressed road increase 1.53~1.68 times the vertical air pollution impact distance. It contributes the decrease of horizontal air pollution impact distance 0.32~0.60 times compare with no barrier case.

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

  • Kim, Jin Guk;Yang, Choong Heon;Yun, Duk Geun
    • International Journal of Highway Engineering
    • /
    • v.17 no.6
    • /
    • pp.117-126
    • /
    • 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.

A Case Study on Cut Slope Failure due to the Geomorphological Factor (지형요인에 의한 절토사면 붕괴사례)

  • Kim, Seung-Hyun;Choi, Ji-Yong;Rhee, Jong-Hyun;Lee, Jung-Yup;Koo, Ho-Bon
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2009.03a
    • /
    • pp.1161-1170
    • /
    • 2009
  • The Roads in Gangwon Province generally was made on purpose to use the military road. In case of these roads, tremendous dangerous cut slopes do exist and its road linear shape was badly designed. In order to make up for this situation, the government has continuously established the new road or performed the public works such as the straight line of the curved road. Soksil 2 cut slope was made through the road improvement work. This has small surface failures and collapses. In spite of dry season, this slope are leaking lots of groundwater at the unbelievable point. So as to get curious phenomenon right, we performed a detailed field investigation, the geomorphological analysis, the stability analysis considering field characteristic and ultimately proposed the countermeasure to make sure stability of Sokil 2 cut slope.

  • PDF

Characteristics of Road Runoff depending on the Rainfall Intensity (강우강도에 따른 노면유출수의 유출 특성)

  • Kim, Seog-Ku;Kim, Young-Im;Yun, Sang-Leen;Lee, Yong-Jae;Kim, Ree-Ho;Kim, Jong-Oh
    • Journal of Korean Society on Water Environment
    • /
    • v.20 no.5
    • /
    • pp.494-499
    • /
    • 2004
  • Growth in population and urbanization has progressively increased the loadings of pollutants from non-point sources as well as point sources. Therefore, it is necessary to manage both point and non-point sources contaminations for protecting water environment and improving water quality. This study investigated the characteristics of pollutant release over a wide range of rainfall intensities as a requisite to control road runoff that accounts for the largest portion of non-point source contamination in urban areas. Samples of runoff rainwater collected from real road surfaces were analyzed for physicochemical parameters such as pH, suspended solids, and heavy metals. A experimental model road ($30cm{\times}30cm$) was also used to evaluate wash-off properties of pollutants deposited on the surface as functions of time and rainfall intensity. Analysis of runoff samples on rain events showed that the pollutant wash-off patterns for heavy metal and suspended solids were similar. This implies that the particles in rainwater adsorb heavy metals. Experiments using the model road made of impervious asphalt demonstrate a strong first flush phenomenon. At high rainfall intensity, approximately 80% of total pollutants were released within 15 min. The pollutant wash-off rates rapidly increase from 9 mm/hr to 12 mm/hr of rainfall intensity and decrease over 12 mm/hr of rainfall intensity.

Development of Autonomous Driving System Verification Environment through Advancement of K-City Virtual Driving Environment (K-City 가상주행환경 고도화를 통한 자율주행시스템 검증 환경 구축)

  • Beenhui Lee;Kwanhoe Huh;Jangu Lee;Namwoo Kim;Jongmin Yoon;Seonwoo Cho
    • Journal of Auto-vehicle Safety Association
    • /
    • v.15 no.1
    • /
    • pp.16-26
    • /
    • 2023
  • Recently, the importance of simulation in a virtual driving environment as well as real road-based tests for autonomous vehicle testing is increasing. Real road tests are being actively conducted at K-City, an autonomous driving test bed located at the Korea Automobile Safety Test & Research Institute of the Transportation Safety Authority. In addition, the need to advance the K-City virtual driving environment and build a virtual environment similar to the autonomous driving system test environment in real road tests is increasing. In this study, for K-City of Korea Automobile Safety Test & Research Institute, using detailed drawings and actual field data, K-City virtual driving environment was advanced, and similarity verification was verified through comparative analysis with actual K-City.

Assessment of Non-point Pollutants and Runoff Characteristics in Urban Area, Korea

  • Park, Jae-Young;Choi, I-Song;Oh, Jong-Min
    • Korean Journal of Ecology and Environment
    • /
    • v.38 no.spc
    • /
    • pp.67-75
    • /
    • 2005
  • The objectives of this study were to understand the runoff characteristics of the non-point sources originating from impervious surfaces and to assess their effect on the aquatic environment in the urban areas. The concentration of pollutants (SS, BOD, COD and T-P) except for T-N showed the highest value in runoff from road, and event mean concentration (EMC) also showed high value from road. The pollutants discharged from road showed a higher concentration in the beginning stage (0 ${\sim}$ 30%) of progressive percentage of rainfall. The contribution percentages of non-point sources by load were 44.9% for SS, 11.2% for BOD, 21.4% for COD, 11.4% for T-N and 8.1% for T-P in the total load of pollutant discharged through sewer. From our results, the road was a significant potential source that deteriorated water quality of the streams and lakes in the vicinity of the urban area during the rain period. Therefore, counter plan is required to reduce pollutant concentration on the road from non-point sources in the urban area. Also, since pollutant concentration in the beginning stage of rainfall was quite high, road cleaning seems to be one of the very useful methods to prevent inflowing of pollutants to the aquatic environment.

Application Methodology of Greenhouse Gases Emission Table for Various Types of Roads and Vehicles (도로기하구조 조건에 따른 차량별 온실가스 배출량 산정사례 적용연구 - 맑은 날씨를 기준으로 -)

  • Lee, Jonghak;Choi, Jaisung;Noh, Kwansub;Hu, Hyejung
    • International Journal of Highway Engineering
    • /
    • v.18 no.1
    • /
    • pp.23-31
    • /
    • 2016
  • PURPOSES : This study aimed to offer a greenhouse gases table to assist a road designer in calculating the greenhouse gases for a road environment when making a decision about an alternative road. METHODS : This study developed an operation mode table of greenhouse gases using the MOVES program. Similar factors for Korean vehicles and fuels are reflected in the MOVES program, which was made in the USA. Finally, a paired t-test was conducted to calculate the site data and MOVES data. Through these studies, a methodology was suggested for calculating carbon emissions based on various types of roads alignments. RESULTS : The site results for a passenger truck on the road were statistically significant when the vehicle speed was above 65 km/h. However, a future study will consider factors for various road alignments and vehicles. CONCLUSIONS : This study will contribute to the theoretical basis for reducing carbon emissions from roads by helping road designers make decisions about road alternatives in terms of the road environment.

Characteristics of Hazardous Air Pollutant Level in Road Tunnels in Seoul (서울시 터널의 유해대기오염물질 농도변화 특성 분석)

  • Park, Jin-A;Lee, Won-Young;Kim, Jin-A;Kim, Ik-Su;Kim, Hyun-Su;Jeong, Jong-Heup;Yun, Jung-Seop;Jung, Kweon;Eom, Seog-Won
    • Journal of Environmental Health Sciences
    • /
    • v.39 no.6
    • /
    • pp.541-549
    • /
    • 2013
  • Objectives: We analyzed the characteristics of hazardous air pollutants (HAPs) in road tunnels in Seoul. Methods: Particle matter ($PM_{10}$), elemental carbon (EC), organic carbon (OC), and 16 species of polycyclic aromatic hydrocarbons (PAHs) in two road tunnels (NS tunnel and HJ tunnel) were sampled and analyzed from 2007 to 2011. Results: Levels of $PM_{10}$ and carbon ingredients which were mainly emitted from diesel-fueled vehicles showed a declining tendency in both road tunnels. PAHs levels in HJ were declining slightly while PAHs levels in the NS tunnel fluctuated considerably and showed an increasing tendency. Conclusions: These results suggested that the abatement project of diesel vehicle emissions by the Seoul metropolitan government from 2007 has had an impact on the reduction of DVE into the air, though there exist many things to consider for analyses.

Implementation of Road Weather Information System Supporting Intelligent Transportation Systems Based on USN (센서 네트워크 기반의 지능형 교통 시스템 지원을 위한 RWIS 구현)

  • Park, Hyun-Moon;Park, Soo-Huyn;Park, Woo-Chool;Seo, Hae-Moon
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.35 no.3B
    • /
    • pp.485-492
    • /
    • 2010
  • Intelligent Transport System(ITS) has been studied in various systems, such as road environment information offering, vehicle short-range wireless/wire communication, vehicle collision preventing and pedestrian safety offering systems. Related to this, the USN technology based on the sensing accuracy for motorists and pedestrians safety, the information reliability, the maintenance and convenience for Sensor Network is highlighted. This study uses various sensors to construct USN to the road, and connect it to the developed RSU so it collects the real-time road environment information and offers it to OBU and Traffic Control Surveillance Center with Road Weather Information System. RSU collects roadside information for driver's safety and analyzes it to offer IP and beacon service according to the service priority to OBU & upper layer terminal. In the upper layer terminal it is developed the IP based Settop Box application program to offer the urban traffic information & road environment, and environment sensor error, etc. Finally, RWIS develops the real-time collection of roadside information to complement the driver's safety to the intelligent traffic system, and presents various service modes with technology convergence.