• 대한교통학회지
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• 제17권3호
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• pp.97-116
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• 1999

The growing demand for the real time traffic information is bringing about the category and number of traffic collection mechanism in the era of ITS. There are, however, two problems in making data into information using various traffic data. First, the information making process of making data into the representative information, for each traffic collection mechanism, for the specified analysis periods is required. Second, the integration process of fusing each representative information into "the information" for each link out of each source is also required. That is, both data reduction and/or data to information process and information fusion are required. This article is focusing on the development of information fusing algorithm based on voting technique, fuzzy regression, and, Bayesian pooling technique for estimating the dynamic link travel time of networks. The proposed algorithm has been validated using the field experiment data out of GPS probes and detectors over the roadways and the estimated link travel time from the algorithm is proved to be more useful than the mere arithmetic mean from each traffic source.

• 한국도로학회논문집
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• 제14권6호
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• pp.85-92
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• 2012

PURPOSES : Since expressways in South Korea are toll roads, many trumpet type interchanges exist, resulting in the installation of loop ramps very frequently. While the travel speed of the main lane is designed to be 100-110 km/h, the structure of a loop ramp is different and is designed for a minimum speed of 40 km/h. In fact, most of the actual travel speeds measured on the ramp exceed the designated speed, which has been a major problem in traffic safety. In this research, a type of pavement marking speed-reduction treatment called the "Peripheral Transverse Line" is installed on expressway loop ramps in order to study the change of driving speeds after the installation. METHODS : To verify statistically the change, this speed-reduction treatment has been installed on the Chungju interchange and the Yeoju junction. The driving speeds before the installation were compared with driving speeds both one month and five monthsafter the installation. RESULTS : As a result, the reductions of the average driving speeds after the treatment were statistically significant. More specifically, the average driving speeds of the Chungju interchange were reduced by 7.1-7.7 % for its tangent road section, and the speeds decreased by 8.5-9.5 % for its curve section. Similarly, in the Yeoju junction, an average speed reduction of 2.9-4.8 % for its tangent section was measured, along with 3.9% long-term speed reduction for its curve section. CONCLUSIONS : Since the pavement marking speed-reduction treatment has been partially proven to be effective from this research, we expect to expand this treatment and re-confirm the effect from a long-term perspective in the future.

• 한국안전학회지
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• 제24권5호
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• pp.101-112
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• 2009

Recently, with the existing speed-management by law enforcements and physical speed-reduction facilities, the country newly adopted Driver Feedback Sign (DFS) system, which displays driving speed in order to guide the driver to an advisable driving condition. DFS is mainly used in school zones due to reasons related to the ITS. Accordingly, because it is predictable that DFS will result in speed-reduction without legal forces and would have an effect on physical speed-reduction facilities, intersection, crosswalks, and road-alignments, this study will try to verify the efficiency of DFS by researching the vehicle speed in national highways and school zones, which have similar conditions to the urban arterial road. In consequence, on national highways, the drivers had a tendency to travel according to the road-environment such as urban arterial road and not reduce speed voluntarily. In school zones, drivers tend to reduce speed in mornings and afternoons when children travel to school or home, showing that the resulting effect is different according to the road-environment where DFS is installed, and the time slot of the DFS.

• 한국도로학회논문집
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• 제14권4호
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• pp.93-101
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• 2012

PURPOSES : Adverse weather conditions such as heavy rain, heavy snowfall, and thick fog and so on have highly affect on the change in traffic conditions on the road. In particular, heavy snowfall causes capacity reduction as well as crash occurrence. This study investigated the effects of snowfall on speed on a freeway. METHODS : Vehicle detection systems data were matched with corresponding weather station data by regression analysis. RESULTS : The results show that the travel speed is reduced by 6.7% under little snowfall and by 12.8% under heavy snowfall. Regarding the speed variation, 8.7% and 114.7% increases are observed under little snowfall and heavy snowfall, respectively. It is also found that 1 cm increase in snowfall leads to 0.4% decrease in travel speed. In addition, the travel speed increases by 0.4% when the temperature increases by $1^{\circ}C$. CONCLUSIONS : It is expected that the outcome of this study will be useful in establishing more effective strategies for winter operations and road maintenance in practice.

• 대한교통학회지
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• 제24권1호
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• pp.29-38
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• 2006

본 연구에서는 고속철도 1단계 개통 이후 대구${\sim}$서울 구간 운행소요시간이 새마을호의 3시간 3분에서 1시간 39분으로 단축되어 대구시민의 지역간 통행 행태에 많은 변화가 있었던 점을 직시하구 대구~서울 구간과 대구${\sim}$대전 구간으로 나누기 지역 간 통행수단 선택모형을 구축하여 2010년 본격적인 고속철도시대를 대비하여 합리적인 지역 간 교통체계를 갖추는데 필요한 정책적인 시사점을 도출하고자 한다. 고속철도 개통 이후 대구시민의 지역 간 통행행태를 분석하기 위해 대구${\sim}$서울 구간과 대구${\sim}$대전 구간으로 지역간 통행을 구분하여 고속철도 승용차, 새마을호, 무궁화호 항공기(대구${\sim}$대전 구간 제외), 고속버스의 선택대안으로 나누어 다항로짓모형을 이용하여 분석하였으며, 설명변수로 차내시간(IVTT), 차내비용(IVTC), 차외시간(OVTT), 차외비용(OVTC)은 일반적 변수(generic variable)로 적용하였고, 나머지 변수들은 대안특유의 변수(alternative-specific variable)로 적용하여 분석하였다. 대구시민의 지역간 통행수단선택행태의 경험적 분석을 위하여 다항로짓모형을 추정하였으며, 최우추정법(method of maximum likelihood estimation)을 활용하였고 LIMDEP Version 7.0이 이용되었다. 본 연구에서 추정된 대구시민의 지역간 통행수단 선택의 다항로짓모형은 통계적 행태적 측면에서 대체로 타당한 결과를 보여주었다. 대구${\sim}$서울 구간의 통행수단 선택모형의 추정결과를 보면 차외시간, 차외비용, 통행빈도, 통행목적 성별, 나이, 직업, 가구 전체의 월평균 소득, 개인 월평균 소득이 지역간 통행수단 선택에 의미 있는 영향을 미치는 것으로 확인되었다. 대구${\sim}$대전 구간의 통행수단 선택모형의 추정결과를 보면 차외시간, 차외비용, 차내시간 통행빈도, 나이(51세 이상 제외), 직업, 가구 전체의 월평균 소득이 지역 간 통행수단 선택에 중요한 영향을 미친다는 사실을 확인할 수 있었다.

• 설비공학논문집
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• 제12권3호
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• pp.251-257
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• 2000

District heating and cooling systems offer highly efficient energy utilization and maintenance by centralizing heat management. More pumping power, however, is required because the water has to travel long distance from heat source to the users. In the present study, a trace of drag reduction additives is added to the District Cooling system to achieve a significant drag reduction and save pumping power. Water-soluble polymers, surfactants, and environment-friendly degradable polymers are used as effective drag reducing additives. Time dependent percent drag reductions are compared for various additive solutions at 100 wppm concentration for different water velocity. Without as an anionic surfactant, copolymer was most effective in percent drag reduction. It is found that there exists an optimal condition when copolymer is mixed with SDS. An environment-friendly degradable polymer, xanthan gum, is found to be a significant drag reduction additive. Ice slurry systems, can give less pressure drops compared with chilled water system for certain condtions. Drag reduction additives were also effective for the ice slurry system.

• 한국ITS학회 논문지
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• 제22권6호
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• pp.32-48
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• 2023

자율주행기술의 발달은 점차 개인화된 통행을 유도하며, 자율주행차량으로의 전환으로 인한 도로운영 측면에서 교통 영향력은 개인차량을 이용한 수요에 의해 가장 큰 영향력을 받는다. 따라서, 교통 영향력 검토를 위해서는 개인통행특성 이해를 기반한 통행발생량 산정이 필요하다. 개인 통행특성 반영이 가능한 Activity-based model(ABM)은 개인의 모든 이동을 다루므로 통행과 통행 사이의 관계에 대한 이해가 선행되어야 한다. 하지만, ABM은 실제 수요예측에서 데이터 구득문제와 같이 많은 한계점이 있다. 따라서, 본 연구에서는 가구통행실태조사자료를 기반으로 통행간 관계를 설명할 수 있는 Tour-based 모형을 활용하였다. 또한, 샘플조사 자료의 전수화를 위해 차량등록대수 및 인구수 데이터를 활용하여 개인차량발생량 보정방안을 제시하였다. 통행발생량 분석결과, KTDB와 비교하였을 때 본 연구에서 전체통행발생량은 약 13% 높았으며, 업무통행의 경우 약 9% 차이로 합리적인 오차수준으로 분석되었다. 결과적으로 본 연구의 궁극적인 목표인 도로운영 측면의 자율주행차량 도입에 따른 수요예측을 위해 Activity-based 모형 구축에 앞서 개인통행특성을 반영할 수 있는 Tour를 기반으로 발생량 보정방안으로 활용될 수 있다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 춘계학술대회 논문집
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• pp.63-70
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• 2000

Light Rail is highlighted for its construction cost and operation ＆ maintenance cost in Korea. However, lack of analysis on driverless operation effect causes many disputes. In this paper, using latest driverless operation cost data. analysed cost reduction effect of it, with comparing present KNR's metropolitan subway signal system. It showed there is enough economic appropriateness B/C 1.241 on interest rate 6%, 1.076 on 8% and 0.943 on 10%, though it couldn't include passenger travel time value.

• 대한교통학회지
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• 제35권6호
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• pp.481-498
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• 2017

교통시설 투자사업에 대한 타당성조사 시 가장 큰 비율을 차지하는 편익항목은 통행시간 절감편익이며, 이는 통행시간가치를 이용하여 산정한다. 현재 예비타당성조사 표준 지침(5판)에서는 1999년 전국 지역 간 통행 조사 자료를 기반으로 산정된 업무통행 대비 비업무통행 통행시간가치의 비율을 이용하여 비업무통행 통행에 대한 시간가치를 산정하였으며, 여기에 수도권 통행목적 비율과 재차인원을 적용하여 수도권에 대한 통행시간가치를 산정하였다. 수도권 통행은 전국 지역 간 통행과 다른 통행특성을 가지고 있다. 수도권 통행의 경우 복합 대중교통 수단을 이용한 환승이 빈번하게 발생하고 있으며, 통근통행에 장시간을 소요하고 있다. 따라서 본 연구에서는 타당성조사 관련 지침의 통행시간가치 산정방법을 개선함으로써 수도권의 통행 특성을 반영한 통행시간가치를 산정하였다. 수도권 통행 특성 반영을 위하여 기존 비업무통행에 포함된 통근통행을 분리하여 통근통행에 대한 통행시간 가치를 별도로 산정하였다. 통근통행 모형과 비업무 통행 모형에 대한 우도비 검정통계량 검정 결과 두 모형은 통계적으로 유의미한 차이가 있는 것으로 분석되었다. 또한 수도권 통합요금제 시행에 따른 통행 여건을 반영하기 위하여 대중교통 통합 모형을 구축하였다. 대중교통 통합모형의 버스와 지하철의 계수 비교결과 두 수단간 계수는 통계적으로 유의미한 차이가 없는 것으로 분석되었다.

• 한국도로학회논문집
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• 제15권2호
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• pp.149-157
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• 2013

PURPOSES : This study is to analysis for benefit and construction cost in underpass for small vehicles. METHODS : The study was performed using the traffic software VISSIM 5.20 for analysis on a variety of traffic conditions and analysed of benefits of changes through analysis of travel speed and travel time after modeling of existing underpass and small vehicle underpass. RESULTS : Results of this study, the benefits will be reduced by the introduction underpass for small vehicles were analyzed because heavy vehicles use the intersection above the underpass. However, it was required economic analysis considering both the benefits reduction and the construction costs reduction because it has the effect of reducing the construction cost. Showed that the difference in benefit changes depending on the v/c and heavy vehicles ratio and construction cost was difference by types of underpass. As a result of performing economic analysis with total benefits and construction cost, it was analyzed to be economical in underpass over a certain size. CONCLUSIONS : The result of this study are expected to be able to contribute to reviewing for feasibility due to the small vehicles underpass introduction and economic analysis. The study is case study to the underpass in Daegu. Therefore, the future requires the calculation of benefits reflect a wider range of traffic conditions and the economic analysis to construction cost calculation for various types of grad separation facilities.