스펀지 도시는 도시가 물을 효율적으로 사용한다는 개념을 강조한다. 도로의 스펀지화는 스펀지 도시 의 가장 직접적인 구현이며, 도시의 침수 및 물 부족 문제를 해결할 수 있다. 본 연구에서는 지닝시 성화 로를 대상으로 하여 성화로 이용에 대한 인식 및 개선수요를 분석하기 위하여 성화로 주민, 환경미화원, 지닝시 택시운전자 및 도로 계획가를 대상으로 현장 인터뷰 및 설문조사를 실시하였다. 조사내용을 바 탕으로 성화로 이용빈도에 대한 인식과 인구통계학적 특성의 유의성을 검증하기 위해 교차분석을 수 행하였다. 선행연구와 성화로 이용 인식분석을 통해 스펀지형 도로, 친환경 생태도로 및 안전형 도로의 3대 도로유형을 설정하였다. 도로유형의 각 항목의 중요도가 성화로침수에 미치는 영향관계를 결정하 기 위해 선형회귀분석을 수행하였으며, 성화로 개선의 방향을 결정하기 위해 AHP 계층분석법을 이용 하여 가중치를 계산하여 각 항목의 중요도 점수를 분석하였다. 분석결과 성화로는 LID 기술, 생태형 비 탈면 설계 및 식생배치가 도로 스펀지화 개선의 주요방향임을 알 수 있다.
PURPOSES : This study is to evaluate environmental improvement effects of underground road project, as a case study of ‘Seobu’underground expressway project in Korea. METHODS : The environmental improvement effects of underground road construction were classified into tree sector in this study – air quality, noise, and thermal environment. To evaluate these effects, this study collected and divided environment dataset into before, during, and after ‘Seobu’underground expressway construction, and compared the change of values with entire city. In addition, the quantification method of environmental improvement effects was suggested based on the literature review. RESULTS : The result of this study indicates that there exist significant improvement effects of urban environment after the construction of ‘Seobu’underground expressway. Specifically, the concentration of particulate matters (PM10) and daytime/nighttime noise, and land surface temperature (LST) were improved along the expressway. In addition, the overall environmental benefit of ‘Seobu’ underground expressway was estimated to 1.15 billion won per year. CONCLUSIONS : To promote systematic and consistent underground road project, it is required to establish legislative system for evalauting and supporting urban improvement effects.
PURPOSES : This study aims to understand the characteristics of accidents involving autonomous vehicles and derive the causes of accidents from road spatial information through autonomous vehicle accident reports. METHODS : For this study, autonomous vehicle accident reports collected and managed by the CA DMV were used as data sources. In addition, spatial characteristics and geometric data for accident locations were extracted by Google maps. Based on the collected data, the study conducted general statistics, text embedding, and cross-analysis to understand the overall characteristics of autonomous vehicle accidents and their relationship with road spatial features. RESULTS : The analysis results for characteristics of autonomous vehicle accidents, applying statistical analysis and text embedding techniques, reveal that the damages caused by autonomous vehicle accidents are often minor, and approximately half of the accidents are triggered by other vehicles. It is noteworthy that accidents where autonomous vehicles are at fault are not uncommon, and when the cause of the accident is within the autonomous vehicle, the accident risk can increase. The accident analysis results using spatial data showed that the severity of accidents increases when on-street parking is present, when dedicated lanes for bicycles and buses exist, and when bus stops are present. CONCLUSIONS : Through this study, geometric and spatial elements that appear to have an impact on autonomous driving systems have been identified. The findings of this study are expected to serve as foundational data for improving the safety of autonomous vehicle operations in the future.
PURPOSES : This study intended to derive a methodology that can evaluate water splash caused by distress on the road surface based on experimental methods and to present quantitatively by analyzing the impact on road users. METHODS : Through literature review, the current problems of road pavement and drainage facility standards, the factors of road splash caused by puddle was selected to measure damage. Field measurements were conducted by setting different conditions for each factors and setting different conditions based on the hypothesis. In addition, water splash by surface distress type and puddle was measured to analyze using statistical techniques from correlation to multi-regression. RESULTS : The maximum and effective distance due to road splash increases as the driving speed, regardless of vehicle load and tyre type. Splash was measured according to the type of road distress to analyze the correlation between the influencing factors, and there was a weak correlation between the width and length of the puddle, depth and the effective distance. In addition, the interaction analysis showed that there was an interaction between the width of the water hole and the depth of puddle. Moreover, based on the multi-regression analysis, it was not statistical significant. This is judged to that the number of data samples used for this analysis is limited because the diversity of puddle conditions cannot be set differently for each type of distress. CONCLUSIONS : Since the distress of depending on the size, depth and shape of the road surface, it is necessary to calculate it and present maintenance standards, so this results present an experimental methodology that can intuitively evaluate damage cased by unestablished puddle. From this results, this is expected to be used as a quantitative indicator to evaluate the satisfaction of road users as a functional performance according to road surface condition.
PURPOSES : This study aims to deduce the appropriate interval of cross passage for small vehicle exclusive roads within urban underground roads to ensure safety.
METHODS : This study evaluated evacuation safety by fire and evacuation simulations. The simulation was applied to a passenger-caronly urban underground road, which was performed in the entry/exit section with a gradient of 6.0% and the mainline on level grade. The values of the variables for the simulations were determined to be close to the actual situation based on of the statistics and the results of previous studies. In the simulation scenario, the cross passage interval was visible. The evacuation safety was evaluated by comparing the “evacuation completion time” and the “smoke diffusion time.” Evacuation safety can be desirable when the evacuation completion time is shorter than the smoke diffusion time.
RESULTS : According to the results of the simulation, the desirable cross passage interval is 180 m for the entry/exit sections with a 6% gradient in passenger-car-only tunnels. This criterion may be prolonged to an interval of 210 m and a width of 0.9 m for the construction reduction, based on the results of the statistical analysis.
CONCLUSIONS : According to the results of this study, the risk indices of the “Small Vehicles Road Tunnel Fire Safety Facility Installation and Management Guidelines” may be supplemented by the tunnel class and the gradient of the entry/exit section. In addition, the guideline may provide an improved interval of evacuation cross passage and the width of the cross passage door by the safety index.
PURPOSES : The purpose of this study is to investigate the effects of urban road characteristics on temperature changes in urban areas using surface thermal temperature.
METHODS : This study measured the surface thermal temperature of each road component from urban roads, analyzed the effect of the road component characteristics and vegetation on temperature, and estimated the regression models.
RESULTS : As a result, the mean temperature was 27.3 ℃ on the roadway, 25.5 ℃ on the vegetated median, and 22.9 ℃ on the sidewalks. The roadside temperature was 26.14 ℃ with surrounding buildings and 23.82 ℃ near green spaces. The temperature with street trees was lower (24.45 ℃) than without (28.38 ℃) while it was 23.96 ℃ with vegetated median and 25.64 ℃ without. The temperatures were lower (24.70 ℃) on the permeable surface than on the impermeable surface (28.38 ℃). Model estimates show that the temperature decreases by 0.007 ℃ with an increase of 1 m² green (permeable space) space and the temperature with buildings tends to be 1.729 ℃ higher than that with green space. As green space increases by 1 m², the temperature tends to decrease by 0.017 ℃ on the roadway and by 0.012 ℃ on the sidewalk. Shade effect models show that street trees with shade affect temperature reduction by -3.884 ℃ on roadways and -3.314 ℃ on sidewalks.
CONCLUSIONS : The results of this study demonstrate the differing effects of road characteristics on temperature. The roadway is more sensitive than the sidewalk to temperature changes and roadside vegetation, ambient green space, and pavement permeability contribute to temperature reduction.
PURPOSES : The purpose of this fundamental study is to estimate the concentration of resuspended road dust in urban areas. This involves examining and measuring the factors that affect the dust concentration and measuring these factors and the concentration directly and indirectly by analyzing the factor-effect relationship of the dust in actual operation.
METHODS : From the literature review, the factors that influence resuspended road dust, including traffic, environment, and weather data of roads and their relationship analysis were obtained to determine the effects of each element on resuspended road dust. The data characteristics and the quantitative changes in the factors when a high concentration of resuspended road dust is generated are analyzed for each condition. The concentrations of the resuspended dust are presented from the perspective of each factor.
RESULTS : When the vehicle speed increased from 60 to 80 km/h, the measured resuspended dust concentration increased by 8㎍/m3 on the average. When the traffic was grouped, the resuspended concentration at 1200-1400 veh/h was 15.84㎍/m3 higher than that of 500-800 veh/h. A high concentration of 60㎍/m3 or more was generated in the SCL high and middle sections, and a high concentration of 10㎍/m3 or more was generated in the SCL low section. Eight cases were observed in the SCL high and middle section at an intense atmospheric wind speed of 3 m/s or more than the SCL level of zero cases. A high concentration of 89.8㎍/m3 resuspended dust was observed after 31 h of rainfall, and the dust concentration gradually decreased by over 50 h. Hence, the passing time after the rainfall, SCL and wind speed, traffic and vehicle speed, and air background (observation) concentration, all have a direct effect on the resuspended dust concentration. Atmospheric temperature and relative humidity have a significant effect on atmospheric dust concentration.
CONCLUSIONS : The quantitative indicators of the factors using an estimation model of resuspended road dust in urban areas can be obtained if the conditions for high concentrations of resuspended dust are established using the quantitative relationship of the resuspended road dust factors presented in this study.
PURPOSES :With the increasing number of older drivers in an aging society, there is a growing need for research and planning on traffic safety for the older drivers using an improved road geometry design. This study also proposed a modified urban road interchange design, which aims to keep the older drivers away from accident-prone and high-traffic areas of the city.METHODS:In this study, we examined accident data records of older drivers to identify accident-prone zones and intersections; we studied the road geometry at these zones and analyzed if it was an underlying cause for higher number of accidents. Based on the research and subsequent analysis, we suggested plans for improvement of road geometry design at these intersections.RESULTS:By studying historic data and analyzing factors that affect the likelihood of accidents of vehicles driven by older drivers and after studying suitable traffic accident prediction models, we identified the major variables that need to be modified at accident-prone intersections, such as the width of a left turn lane at an intersection and the radius of the right turn lane at a street corner. The results have a significance probability of less than 0.001 and a 95% confidence level. To improve safety at the identified intersection, this study suggests the installation of a left-turn-lane-shaped Positive Offset and a right-turn-lane-shaped Slip Lane concept and an adjustment of intervals between intersections.
PURPOSES: According to accident statistics for road built in 2004, the ratio of accidents on frozen roads to normal roads is 0.9%, whereas the fatality ratio is 2.7%. The risk of accidents on frozen roads is very high. Measures taken every year to prevent traffic accidents of frozen roads in the winter season are still insufficient. Additionally, measures have been established mainly on rural roads. Therefore, for urban roads, analyses and measures to prevent accidents are lacking. In this study, data on accidents on frozen roads was used to search for the causes behind these accidents and measures to reduce accidents have been recommended.
METHODS: In this study, collected data from the TAMS (Traffic Accident Management System), which were collected by the Seoul National Police Agency was used. The data were divided into vehicle, people, and condition of road. The analytical model used here was the Logistic Regression Model, which is frequently used for traffic safety and accident analysis. This study uses the odds ratio analysis to search for variables related to frozen road traffic accidents in each category. A total of 18 out of 47 variables were found to be the causes of accidents.
RESULTS: From the results of the comparative analysis of 18 variables, the category of the condition of the road was found to be the most critical. Contrary to expectations, more accidents occurred in clear weather than in other conditions. Accidents on bridges occurred frequently, and its odds ratio was the highest compared with other road types. When BPT is operated, the probability of accidents on frozen roads is lower than in general conditions, and accidents occurred frequently on roads with less than four lanes.
CONCLUSIONS : Based on the results of this study, suggestions for reducing the risk of future domestic road accidents in freezing conditions are indicated as follows. First, it is necessary to perform a technical review of the urban road traffic accidents caused by frozen roads. Second, it is necessary to establish criteria for the study of the road environment based on the major causes of road accidents on frozen roads. Third, improvements in urban road environmental factors should be made.
본 계획의 대상지는 강원도 동해시 부곡동 태평북로로 발한동주민센터에서 발한삼거리를 지나 구 버스터미널까지 입지하고 있는 가로구간이다. 계획의 기본 방향은 첫째, 구 도심지의 재정비로 거리활력을 창조하고 둘째, 도시디자인 가이드라인에 맞추어 설계되어야하고, 마지막으로 환경친화적이며 주변 환경과의 조화에 중점을 두고자 하였다. 가로환경의 디자인 기본방향을 통합디자인 컨셉으로 설정하였고 과도한 디자인을 적용하는 것보다는 보행의 안전성과 연속성이 무엇보다 가장 중요하다는 것에 중점을 두었다. 본 계획은 보다 합리적이고 체계적인 가로를 조성하고 보행자 환경을 개선하여 낙후된 구 도심권의 상권을 회복하고 지역균형발전을 촉진하며 경관개선을 통한 주민 삶의 질 향상에 기여할 것 이다.
PURPOSES : The purpose of this study is to check the possibilities of traffic pattern analysis using MatSIM for urban road network operation in incident case. METHODS : One of the stochastic dynamic models is MatSIM. MatSIM is a transportation simulation tool based on stochastic dynamic model and activity based model. It is an open source software developed by IVT, ETH zurich, Switzerland. In MatSIM, various scenario comparison analyses are possible and analyses results are expressed using the visualizer which shows individual vehicle movements and traffic patterns. In this study, trip distribution in 24-hour, traffic volume, and travel speed using MatSIM are similar to those of measured values. Therefore, results of MatSIM are reasonable comparing with measured values. Traffic patterns are changed according to incident from change of individual behavior. RESULTS : The simulation results and the actual measured values are similar. The simulation results show reasonable ranges which can be used for traffic pattern analysis. CONCLUSIONS : The change of traffic pattern including trip distribution, traffic volumes and speeds according to various incident scenarios can be used for traffic control policy decision to provide effective operation of urban road network.
From December 2014 to November 2015, an automatic weather system (AWS) was installed over a wide road of Daegu to continuously measure meteorological factors and surface temperature. We investigated the effective operating period of the clean-road system using the daily maximum and minimum air and asphalt surface temperatures, with the aim of creating an optimum thermal environment. The clean-road system was installed over a part of the broad way of Dalgubul(Dalgubul-Daero) by Daegu Metropolitan City in 2011. Until now, the clean-road system has been operated from the middle of April to the end of September. We assumed that it was desirable that the clean-road system could be operated when the discomfort index was above 55. In conformity with the conditions, we concluded that the optimum operation period of the clean-road system is from the end of March to about the middle of October.
Based on the study of chloride migration coefficient and hydration heat evolution, it was found that the use of ternary blended cement was effective to achieve desired service life and minimum crack index. On the other hand, a high level of compressive strength is required for marine concrete mix design.