• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.99-111
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• 2002

전산기술의 발달에 힘입어 근래에 모의실험을 이용한 연속교통류의 미시적 분석이 활발히 수행되고 있고 다양한 모의실험 전산모형이 소개되고 있다. 미시적 연속교통류 전산모의실험은 차량추종모형과 차로변경모형을 적용하여 다양한 운전자들의 차량운행행태를 모사하여 분석하는 실험이다. 전산모형은 난수를 토대로 차량의 자유속도와 초기 발생 차로를 배정하기 때문에 낮은 자유속도를 할당받은 차량이 높은 속도의 차로(예:1차로)로 발생되는 경우가 발생한다. 많은 모의실험모형이 사용하고 있는 차로변경의 가정이 "운전자는 자신이 원하는 속도(자유속도)를 유지한다"는 것이며 그러한 가정만의 적용으로 인해 현실적이지 않은 차로 이용률이 결과되고, 따라서 전산모형을 통한 교통류 흐름분석에 문제를 제공하고 있다. 본 논문에서는 미국 도로국에서 20여년 동안 개발되고 수정되어왔으며 현재 실용적으로 가장 많이 사용되고 있는 Freeway Simulation(FRESIM) 전산모형이 내재한 차로변경모형을 토대로 고속도로 기본구간에서의 선택적 차로변경모형을 제시한다. 제시된 모형에서는 (1)저속의 선행차량이 고속의 후행차량에게 차로를 양보하는 가정이 새롭게 추가되고 (2)FRESIM모형에서 사용하는 상수값을 국내 현장조사를 통하여 도출된 분포식을 통한 값으로 대체하였다. 수집된 자료분석결과 연속 교통류에서의 15% 차두시간은 1.34초이며 차로변경시간은 평균 2.22초인 F분포를 따르고, 자유속도는 정규분포를 따르는 것으로 결과되었다. 모의실험결과 무작위난수를 토대로 배정된 차로로 생성된 차량들이 새롭게 제시된 차로변경모형의 적용으로 현장 차로이용률을 95% 신뢰수준에서 모사하는 것으로 분석되었다.

• Journal of Korean Society of Transportation
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• v.20 no.6
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• pp.69-80
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• 2002

차로변경이 발생하는 두 가지 상황 즉, 강제 차로 변경과 선택적 차로 변경 중, 선택적 차로변경 상황에서 운전자가 수락 가능한 간격을 발견했을 때, 차로별 속도 차가 차로 변경 의사결정에 미치는 영향을 모사할 수 있는 모형식을 추정하였다. 즉, 선택적 차로 변경은 운전자의 차로 변경 여부에 대한 상황판단과 함께 목적 차로의 간격 수락여부에 대한 의사결정으로 이루어지는데, 본 논문에서는 목적 차로에 수락 가능한 간격이 존재할 경우 차로별 속도차가 운전자의 의사결정에 어떤 영향을 미치는지에 대해 분석하였다. 이를 위해, 운전자 의 의사결정에 영향을 미칠 수 있는 다른 요소 즉, 중차량, 기하구조, 및 합·분류의 영향을 최소화하는 지점을 선택하여 표본조사를 실시하였으며, 보다 설명력 있는 모형식을 얻기 위해 상관분석 등을 수행하여 불필요하다고 생각되는 변수는 제외시켰다. 또한, 운전자의 희망속도와 주행 속도 차에 의한 영향을 반영하기 위해 현 차로 속도를 부가적인 변수로 추가하였으며, 계수추정은 통계패키지인 SAS를 이용하였는데, 자료분석에 있어, 속도차 구간에 따라 다른 간격수락 특성을 보여 차로별 속도차를 0∼2.0m/s구간과 2∼11.52m/s구간으로 나누어 분석을 수행하였다. 분석결과 속도차 0∼2.0m/s구간에서는 속도차가 증가할수록 차로 변경률이 높아졌으나, 2∼11.52m/s구간에서는 오히려 차로 변경률이 낮아지는 것으로 나타났는데, 이는 속도 차의 증감에 대해 운전자로 하여금 차로 변경을 유도하는 요소와 함께 저항하게 하는 요소가 있다는 것을 알 수 있었다. 분석결과. 2.0m/s 이상의 속도차에서 차로변경에 대한 저항이 상대적으로 크게 작용한다는 것을 알 수 있었으며, 도로 설계시 이를 반영하여 도로기하구조 및 안전성 등을 향상시킬 수 있을 것으로 보인다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3D
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• pp.329-334
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• 2009

The various behaviors of vehicular traffic flow are generated through both car-following and lane-changing behaviors of vehicles. Especially lane-usage varies by lane-changing behaviors. In the area of microscopic vehicle simulation, a lane-changing model connected to a car-following model parallel is essential to generate both various traffic flows relationships and laneusages. In Korea, some studies on car-following models have been reported, but few studies for lane-changing models stay in the beginning stage. In this paper, a two-lane changing model for the simulation modeling of large freeway network is introduced. The lane-changing model is developed based on CA (Cellular Automata) model. The developed model is parallel combined with an existing CA car-following model and tested on a closed link system. The results of simulation show that the developed model generates the various behaviors of lane usage, which existing CA lane-changing models could not generate. The presented model is expected to be used for the simulation of more various freeway traffic flows.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.06a
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• pp.332-333
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• 2018

본 논문에서는 딥러닝 기반의 주행 차로 인식 기법을 활용한 차선 변경 검출 기술을 제안한다. 제안한 방법은 주행 차로, 좌우 차로, 차량 등 3 종의 이미지 데이터를 학습, 검증, 실험 데이터로 나눠 활용하였다. 주행 차로 및 차선 변경 인식을 위하여 변형된 AlexNet 모델을 개발하였다. 실험 결과 주행 차로 69.45%, 좌우 차로 66.9%, 차량 76.4%의 인식률 결과를 보여 기존 패턴인식 방법과 비교하여 우수한 결과를 보였다.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.278-291
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• 2017

Effective installation and operations of traffic safety signs in the advance warning area is of considerable interest for safer traffic management at freeway work zones. This study evaluated the feasibility of traffic safety sign installation based on a driving simulation experiment to take drivers' responsive characteristics into consideration. Both the compliance rate for speed limit and a lane-changing safety index were used for evaluating a set of driving simulation scenarios. It was identified that providing speed limit signs to reduce speed in advance and afterward guiding lane-changing could lead to safer maneuvering of vehicles entering work zones. The outcomes of this study are expected to be useful for revising freeway work zone management policies toward crash prevention.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.332-347
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• 2017

Analysis of the interaction between the automated vehicles and manual vehicles is very important in analyzing the performance of automated cooperative driving environments. In particular, the automated vehicle platooning can affect the driving behavior of adjacent manual vehicles. The purpose of this study is to analyze the lane change behavior of the manual vehicles in automated vehicle platonning environment and to conduct the experiment and questionnaire surveys in three stages. In the first stage, a video questionnaire survey was conducted, and responsive behaviors of manual vehicles were investigated. In second stage, the driving simulator experiments were conducted to investigate the lane change behaviors of in automated vehicle platonning environments. To analyze the lane change behavior of the manual vehicles, lane change durations and acceleration noise, which are indicators of traffic flow stability, were used. The driving behavior of manual vehicles were compared across different market penetration rates (MPR) of automated vehicles and human factors. Lastly, NASA-TLX (NASA Task Load Index) was used to evaluate the workload of the manual vehicle drivers. As a result of the analysis, it was identified that manual vehicle drivers had psychological burdens while driving in automated vehicle platonning environments. Lane change durations were longer when the MPR of the automated vehicles increased, and acceleration noise were increased in the case of 30-40 years old or female drivers. The results from this study can be used as a fundamental for more realistic traffic simulations reflecting the interaction between the automated vehicles and manual vehicles. It is also expected to effectively support the establishment of valuable transportation management strategy in automated vehicle environments.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4D
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• pp.305-311
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• 2012

With the rapid deployment of hipass$^{(R)}$, the congestion is inevitable due to the operation of the hipass lane system. Recently, SMART Highway project have developed a multi-lane mainline tolling system, called SMART Tolling system. To analyze the effectiveness of the system in terms of capacity, this study tries to estimate the capacity and its improvement of multi-lane tolling system based on current hipass$^{(R)}$ data. The methodology uses the saturation time headway. This follows three steps; 1) estimate the saturation time headway, using hipass$^{(R)}$ data, and capacity. 2) estimate two factors (the first one is dividing the one side lane width and lateral clearance factor ($f_w$) into two side one, the second one is dividing the capacity of hipass lane operating a circuit breaker into the capacity of hipass lane not operating, the last one is increasing factor of lane width). 3) calculate the capacity of multi-lane mainline tolling system. The results of method produced 2172~2187 veh/hour as smart tolling capacities, respectively. Those are higher about 370 veh/hour than the values from existing literature reviews. Additionally, saturation time headways were identified as lower by 0.5 seconds/veh than existing headways based on hi-pass$^{(R)}$ based one, which naturally implies the improvement in capacity. Some limitations and future research agenda have also been discussed.

• Journal of Korean Society of Transportation
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• v.29 no.4
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• pp.7-15
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• 2011

Emerged in early 1990s, so called 'Quick service' industry that provides faster delivery of small parcels than regular mail service accelerated use of motorcycles. As the economic grows, use of large bicycles (more than 250CC displacement) for leisure purpose has also rapidly increased. Traffic crash data clearly shows the increasing trend in motorcycle crashes. The ratio of motorcycle involved crashes out of total has increased from 5.7% in 2005 to 8.3% in 2008, and similar trend can be found in fatalities ratio as well. In this study, we assess the level of risk when motorcycles operate on motorways by analyzing traffic rule violation ratio, lane change behaviour, driving speed behaviors of motorcycles in Uninterrupted Traffic Flow Facilities and using PC-CRASH simulation we also calculate car shock impulses occurred when an accident happens. Analysis result shows that the motorcycle is different from the car in terms of lane change timing and average speed, and also shows motorcycle drivers tends to conduct more improper driving behavior particularly when traffic is congested. The results from this study could be usefully applied when the law enforcement agent decides whether bicycles shall be allowed to use motorways. The result could be also utilized as fundamental information for further study of bicycles' driving behavior.

• Journal of KIISE:Software and Applications
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• v.27 no.12
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• pp.1174-1182
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• 2000

본 논문은 주행중인 자동차 환경에서 운전자의 안전성 및 편의성의 동시 확보를 위하여, 보조적인 스위치 조작 없이 상시 음성의 입, 출력이 가능한 시스템을 제안하였다. 이대 잡음에 강인한 threshold 값을 구하기 위하여, 1.5초마다 기준 에너지와 영 교차율을 변경하였으며 대역 통과 여과기를 이용하여 1차, 2차로 나누어 실시간 상태에서 자동으로, 정확하게 끝점 검출을 처리하였다. 또한 남성, 여성을 피치검출로 구분하여 모델을 선택하게 하였고, 주행중인 자동차 속도에 따라 가장 적합한 모델을 사용하기 위하여 Idle-40km, 40-80km, 80-100km로 구분하여 남성, 여성 모델을 각각 구분하여 인식할 수 있게 하였다. 그리고, 음성의 특징 벡터와 인식 알고리즘은 PLP 13차와 OSDP(one-Stage Dynamic Programming)을 사용하였다. 본 실험은 서울시내 도로 및 내부 순환도로에서 각각 속도별로 구분하여 화자독립 인식 실험을 한 결과 40-80km 상태에서 남자는 96.8%, 여자는 95.1%, 80-100km 상태에서는 남자 91.6%, 여자는 90.6%의 인식결과를 얻을 수 있었고, 화자종속 인식실험 결과 40-80km 상태에서 남자는 98%, 여자는 96%, 80-100km 상태에서는 남자는 96%, 여자는 94%의 높은 인식률을 얻었으므로, system의 유효성을 입증하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1D
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• pp.25-32
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• 2009

Currently, various types of TDM (Transportation Demand Management) policies are being studied and implemented in an attempt to overcome the limitations of supply oriented policies. In this context, this paper addressed issues of effectiveness and possible domestic implementation of the HOT lane. The possible site of implementation selected for this simulation study is part of the Kyung-bu freeway, where a dedicated bus lane is currently being operated. Minimum length of distance required in between interchanges and access points of the HOT lane for vehicles to safely enter and exit the lane, and traffic management policies for effectively managing the weaving traffic trying to enter and exit the HOT lane were presented. A 5.2km section of freeway from Ki-heuing IC to Suwon IC and a 8.3km section from Hak-uei JC to Pan-gyo JC have been selected as possible sites of implementation for the HOT lane, in which congestion occurs regularly due to the high level of travel demand. VISSIM simulation program has been used to analyze the effects of the HOT lane under the assumption that one-lane HOT lane has been put into operation in these sections and that the lane change rate were in between 5% to 30%. The results of each possible scenario have proven that overall travel speed on the general lanes have increased as well by 1.57~2.62km/h after the implementation of the HOT lane. It is meaningful that this study could serve as a basic reference data for possible follow-up studies on the HOT lane as one effective method of TDM policies. Considering that the bus travel rate would continue increase and assuming the improvement in travel speed on general lanes, similar case study can be implemented where gaps between buses on bus lane are available, as a possible alternative of efficient bus lane management policies.