• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.29 no.5D
• /
• pp.635-644
• /
• 2009

Image processing technique in the outdoor environment is very sensitive, and it tends to lose a lot of accuracy when it rapidly changes by outdoor environment. Therefore, in order to calculate accurate traffic information using the traffic monitoring system, we must resolve removing shadow in transition time, Distortion by the vehicle headlights at night, noise of rain, snow, and fog, and occlusion. In the research, we developed a system to calibrate the amount of traffic, speed, and time occupancy by using image processing technique in a variety of outdoor environments change. This system were tested under outdoor environments at the Gonjiam test site, which is managed by Korea Institute of Construction Technology (www.kict.re.kr) for testing performance. We evaluated the performance of traffic information, volume counts, speed, and occupancy time, with 4 lanes (2 lanes are upstream and the rests are downstream) from the 16th to 18th December, 2008. The evaluation method performed as based on the standard data is a radar detection compared to calculated data using image processing technique. The System evaluation results showed that the amount of traffic, speed, and time occupancy in period (day, night, sunrise, sunset) are approximately 92-97% accuracy when these data compared to the standard data.

• Journal of Korean Society of Transportation
• /
• v.31 no.1
• /
• pp.15-24
• /
• 2013

To accommodate urban concentration of population, multi-purpose super-tall buildings have been introduced, but they induce many travel demands causing regional traffic problems. While several travel demand management policies such as transit promotion or parking limits are presented to alleviate such problems, transportation infrastructure are still insufficient to meet high demands. In this study, super-tall buildings are categorized by scale and purpose, then mode-specific derived demand is estimated using modal share of each category. Optimal transportation infrastructure level is determined by condition-based average changing amount yielded by street network delay (in case of road) or the number of transit routes (in case of transit).

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.12 no.6
• /
• pp.116-126
• /
• 2013

Weather factor to affect driver's driving environment are due to changes in weather conditions is caused rainfall, snowfall, fog etc and the reducing of road capacity and because deteriorating weather could be affect the headway and vehicle speed and the decrease in lane caused by an accident occurs that was analyzed that bad weather occur congestion greater than on the clear day. Bad weather to reduce of the driver's visibility was analysed the sensitive to changes in travel speed and traffic accident to appears high characteristics according to weather conditions on the expressway(higher speed) than general road. As a result, visibility have been determined to be important factor in changes of the highway traffic flow characteristics. Therefore, in this study, we selected traffic volume and travle speed that have a major impact on high-speed expressway basic segments as importance effect factor and we selected to subject of analysis among the Metropolitan Expressway that it could be obtained certain level of traffic volume data and we studied the changing of expressway traffic flow due to change visibility after the collecting of meteorological and traffic data. In order to perform this study, data collection and analysis methods were established through the existing literature and we had selected level of visibility of the expressway and we had performed the statistical verification. Finally, we had calculated the rate of change of expressway traffic flow characteristics due to visibility and we had come up with a way to apply at capacity and service level analysis.

• Journal of Korean Society of Transportation
• /
• v.21 no.5
• /
• pp.83-95
• /
• 2003

This study aims to develop travel time estimation and prediction models on the freeway using measurements from vehicle detectors. In this study, we established a travel time estimation model using traffic volume which is a principle factor of traffic flow changes by reviewing existing travel time estimation techniques. As a result of goodness of fit test. in the normal traffic condition over 70km/h, RMSEP(Root Mean Square Error Proportion) from travel speed is lower than the proposed model, but the proposed model produce more reliable travel times than the other one in the congestion. Therefore in cases of congestion the model uses the method of calculating the delay time from excess link volumes from the in- and outflow and the vehicle speeds from detectors in the traffic situation at a speed of over 70km/h. We also conducted short term prediction of Kalman Filtering to forecast traffic condition and more accurate travel times using statistical model The results of evaluation showed that the lag time occurred between predicted travel time and estimated travel time but the RMSEP values of predicted travel time to observations are as 1ow as that of estimation.

• Proceedings of the Korean Society of Disaster Information Conference
• /
• 2023.11a
• /
• pp.255-256
• /
• 2023

본 연구에서는 코로나19로 인하여 전국적으로 전례 없는 통행체계 위축 등 통행행태 변화가 발생되어 수도권 및 인천시 지역적 세부 통행체계에 대하여 네트워크 중심성 분석을 통하여 지역별 교통 거점과 외부 영향에 따른 지역적 교통 거점 변화를 비교 분석하였다. 또한, 대중교통 이용통행 분석 결과, 코로나19 유행 시기별로 통행량이 크게 감소됨에 따라 버스, 지하철 등 수단별 대책 마련하는데 기여할 것으로 판단된다.

• Journal of Korean Society of Transportation
• /
• v.13 no.2
• /
• pp.19-42
• /
• 1995

1980년대 후기부터 교통정책의 우선 목표는 지역경제성장 자체가 교통문제를 스스로 해결할 수 있도록 하기 위하여 종래의 관리 중시의 정책은 다시 토지이용 정책으로 변화를 초래하엿다. 오늘날 대도시는 개개 졍제활동 주체들의 동적인 경제 행태에근거하여 분산구조를 띠고 있다. 이러한 동적인 경제행태에 미치는 요소들은 교통체계와 토지이용과 상호연관성의 연구에 필수적인 지가, 인구분포, 통행행태등이다. 그러나 전통적인 단핵도시 모형은 대도시의 분산구조형태의 동적인 과정을 설명하는데는 한계가 있다. 본 연구는 대도시의 변천과정을-도심 및 부심의 출현·소멸현상-설명함으로써 도시교통정책 필수적인 입지와 통행패턴에 대한 새로운 동태적 이론의 기초를 제공하는데 그 목적이 있다. 이를 위하여 지역경제 성장과 도시공간구조와의 동태적관계를 통합하는 토지이용과 교통의 연속 모형을 개발·응용하였다. 개발된 모형에서는 교통량에 따른 교통비용, 도시공간구조로 인한 외부효과들, 경제활동주체들의 비동질성, 이주비용, 그리고 집적 이익등이 매기마다 내생적으로 결정되어 대도시의 공간구조 변화를 설명한다. 경제 호라동주체들간의 ? 호물리적 교류는 소득 증대에 의하여 경제구조가 변함에 따라 새로이 결정된다. 가상적 도시와 자료를 가지고 실험한 결과 비동질적인 경제주체들의 불균형적 성장이 장기적으로 도시구조에 영향을 미치며, 기본적인 경제행위에 따라 장기동태적인 과정을 통하여나타나는 도시의 분산구조형태의 중요성을 보여주고 있다. 또한 교통비용의 변화에 따른 민감도분석을 통하여 모형의 실용성을 검정하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.23 no.2
• /
• pp.32-49
• /
• 2024

In this paper, we analyzed the impacts of road traffic conditions and speed limit changes on traffic flow and safety. Travel speed and moving speed were set as traffic flow indicators and'moving speed-travel speed',speed deviation, large speed deviation ratio, and number of conflicts were set as safety indicators, and the impacts of changes in road traffic conditions and speed limits on these were analyzed. According to the analysis results, the speed limit had a significant impacts on the traffic indicators, but did not significantly affect the safety indicators. As a result of the statistical validity test, it was proven that the traffic flow index increases as the speed limit increases. However, although safety indicators often increase, their validity has not been proven statistically. Therefore, if the speed limit is set and operated by properly considering the traffic flow status according to various road conditions and changes in traffic volume, it can be said to match the speed at which drivers drive and improve traffic flow and safety. Therefore, it is expected that calculating the speed limit considering the traffic flow indicators and safety indicators presented in this paper and operating the speed limit according to changes in traffic volume will contribute to stabilizing the traffic flow on the road.

• Journal of Korean Society of Transportation
• /
• v.17 no.5
• /
• pp.69-78
• /
• 1999

This paper defines the reliable based route choice Principle and formulates the reliability based equilibrium traffic assignment using the Principle. The reliability is defined as the difference of travel demand and capacity using the interference theory of the system engineering. An efficient solution a1gorithm based on Frank-Wo1fe algolithm is Presented to calculate and compare the reliability based traffic assignment with conventional travel time based assignment using small and large scaled road networks. The results show that reliability based traffic assignment converges to equilibrium solution in a reasonable computing time. The equilibrium link flows between reliability and travel time based traffic assignment differ each other in the sense that reliability based assignment is assigned based on the maximum difference of travel demand and link capacity whilst travel time based is assigned on the shortest travel time.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.20 no.6
• /
• pp.14-25
• /
• 2021

With the spread of COVID-19 and the government policy of social distancing, the demand for subways and buses is decreasing, whereas the demand for public bicycles and personal transportation is increasing. Hence, research is needed to understand the characteristics of this phenomenon and to prove the statistical reliability of the correlation between the subway and shared bicycle demands. In this study, the correlation between the number of confirmed COVID-19 cases and the replacement rate of subway and public bicycle demands was examined, but the statistical significance was not significant. However, during the period of September to December 2020, in which the number of confirmed COVID-19 cases in Seoul started to increase rapidly, there was a correlation between the number of confirmed COVID-19 cases and the replacement ratio. If the number of confirmed COVID-19 cases increases by more than a certain number, public bicycles are expected to play a significant role as alternates to the subways. It is expected that the role of public bicycles will increase, and that it is possible to suggest the direction of transportation operation and policy establishment for the continuation of COVID-19 countermeasures in field demonstration after elementary technology development. It is also expected that this study will suggest a direction for future development and policymaking.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2001.11a
• /
• pp.261-262
• /
• 2001

도서지역의 경제산업 활동으로 인한 에너지 소비와 교통량의 지속적인 증가는 공해방지와 환경개선 등을 위한 노력에도 불구하고 도시 대기질을 보다 심각한 상태로 오염시키고 있다. 이러한 대기오염물질 중 입자상 오염물질의 경우 그 입자의 크기는 100$\mu\textrm{m}$보다 큰 것에서부터 0.01$\mu\textrm{m}$ 정도까지 다양한 크기로서 대기내에 존재하며, 2.5~10 $\mu\textrm{m}$이하의 미세분진은 태양광의 산란 등을 통해 시정을 감소시키고, 태양복사에도 영향을 주어 지구와 대기간의 복사평형에도 변화를 초래한다(김필수 등, 1991; 문길주 등, 1994). (중략)