PURPOSES : A methodology for estimating micro-emission factors using vehicle trajectory data collected from navigation and DTG devices and basic emission factors for each vehicle type of the MOtor Vehicle Emission Simulator (MOVES) is presented. The methodology can calculate micro-emissions based on only the traffic volume and average speed for each vehicle type. METHODS : Cluster analysis was performed by accumulating the trajectories of individual vehicles on a specific road section into speed groups in which vehicles drove with the same range of average speed. Then, the micro-emission factors were estimated for each speed group. RESULTS : Using the vehicle trajectory data revealed that the emissions calculated from micro-emission factors estimated by the proposed methodology were similar to the sum of the emissions calculated from the vehicle trajectories for each vehicle. CONCLUSIONS : The micro-emission factor database for each road type and vehicle type proposed in this study should be useful for estimating vehicle emissions on the road. The proposed method can calculate emissions in the same way as the macroscopic analysis method, using the traffic volume, average speed, and link length.

최근, 근거리 무선통신(DSRC), GPS 등 위치기반 및 전송기술에 힘입어 하이패스, 교통카드, 차량 내비게이션 등 다양한 데이터의 확보가 가능한 환경이 되었다. 이로 인하여 통행자의 이동과정과 교통운영 과정에서 다양한 데이터가 끊임없이 생성되고 축적되고 있으며, 향후 자율주행차량의 등장으로 그 양은 폭발적으로 증가될 것으로 판단된다. 고속도로의 경우 본선에 설치되어 있는 DSRC(Dedicated Short Range Communication) 시스템을 통하여 도로변 기지국(RSE)과 주행 차량 내 OBU와 무선통신으로 교통정보를 수집하고 있다. DSRC 시스템에서는 개별차량의 통행 궤적, 링크 통행속도 등이 수집되며, 고속도로에 설치된 총 978개소의 도로변 기지국(RSE)에서 전체 고속도로 이용차량의 약 30% 차량에 대해서 정보를 수집하고 있다 본 연구에서는 고속도로에서 수집되는 개별차량의 경로정보를 수집 및 가공하여 분석을 수행하였다. 분석의 시간적 범위는 대표 평일과 명절을 대상으로 하였으며, 세부적인 분석항목은 차종별, 시간대별로 선택하는 통행경로 및 국도우회 행태, 특정도로 구간을 통과하는 차량의 기종점, 통행거리 및 통행발생 특성 등이다.분석을 통해 고속도로 이용차량의 교통상황에 따른 통행경로 및 통행거리, 통행시간에 대한 특성이 평일과 명절에 어떻게 달라지는지, 경로별 통행시간에 따른 통행경로 이용률의 변화 등을 파악할 수 있었다. 또한 이러한 분석을 통해 산출된 결과를 고속도로 교통관리 정책에 활용할 수 있는 세부 방안을 도출하였다.

PURPOSES: The density in uninterrupted traffic flow facilities plays an important role in representing the current status of traffic flow. For example, the density is used for the primary measures of effectiveness in the capacity analysis for freeway facilities. Therefore, the estimation of density has been a long and tough task for traffic engineers for a long time. This study was initiated to evaluate the performance of density values that were estimated using VDS data and two traditional methods, including a method using traffic flow theory and another method using occupancy by comparing the density values estimated using vehicular trajectory data generated from a radar detector. METHODS: In this study, a radar detector which can generate very accurate vehicular trajectory within the range of 250 m on the Joongbu expressway near to Dongseoul tollgate, where two VDS were already installed. The first task was to estimate densities using different data and methods. Thus, the density values were estimated using two traditional methods and the VDS data on the Joongbu expressway. The density values were compared with those estimated using the vehicular trajectory data in order to evaluate the quality of density estimation. Then, the relationship between the space mean speed and density were drawn using two sets of densities and speeds based on the VDS data and one set of those using the radar detector data. CONCLUSIONS: As a result, the three sets of density showed minor differences when the density values were under 20 vehicles per km per lane. However, as the density values become greater than 20 vehicles per km per lane, the three methods showed a significant difference among on another. The density using the vehicular trajectory data showed the lowest values in general. Based on the in-depth study, it was found out that the space mean speed plays a critical role in the calculation of density. The speed estimated from the VDS data was higher than that from the radar detector. In order to validate the difference in the speed data, the traffic flow models using the relationships between the space mean speed and the density were carefully examined in this study. Conclusively, the traffic flow models generated using the radar data seems to be more realistic.

ABSTRACT PURPOSES: It is desirable for buses to be parallel to the face of the bus shelter at a bus stop. In this way, passengers can safely use the buses without moving into the vehicle area. The study was a review of the current bus bay geometric guidelines, to determine whether they lead buses to stop parallel to the face of the bus shelter by analyzing vehicle trajectory. METHODS : A commercial software program for vehicle trajectory analysis was used under our assumptions about bus dimensions and geometric values. The final position of the bus was analyzed for multiple trajectory simulations, reflecting various geometric alternatives. RESULTS: Within the scope of the study, we concluded that the current design guidelines need to be revised by the design values suggested by the study. CONCLUSIONS : The results of the study suggested alternative design values for bus bay geometry, based on the assumption that buses should be parallel to the face of the bus shelter in order to prevent passengers from moving into the vehicle area.

PURPOSES : The lack of details of design guideline for zig-zag shaped section approaching central bus stop leads an traffic accident proneness. So, this study analysed the geometric elements of central bus stop area in terms of vehicle dynamics and suggested design alternatives. METHODS: The study analysed a dynamic behaviour of bus moving in and out of zig-zag shaped section using Auto-Turn under scenarios. Based upon dynamic analysis, the study found out the width of overtaking lane is the most influential factor for a safe moving at zig-zag alignment. RESULTS : The width of overtaking lane at design speed of 40, 50, and 60 km/h respectively was suggested given taper ratio of 1 to 10 required for Bus Rapid Transit (BRT), and the lane width is not wider than 4.0m which possibly makes two vehicles using the same lane. Also, the width of overtaking lane which mitigates the taper ratio was suggested with the same restriction about the maximum lane width. CONCLUSIONS: The results of the study can be used to prepare a design guideline on zig-zag shaped alignment of central bus exclusive lanes. The more stable moving is expected by applying the design alternatives suggested, therefore the lower rate of traffic crashes at the vicinity of central bus stops.

차량의 바퀴궤적의 횡방항 변동을 의미하는 원더링(wandering)은 포장의 설계 및 유지보수를 위하여 중요한 요소임에도 불구하고 계측의 어려움 때문에 심도 있게 다루어지지 못하고 있다. 본 연구에서는 왕복 2차로(3.5m차로 폭)와 4차로(3.25m 및 3.5m 차로 폭)인 일반국도 직선 구간에서 차량 바퀴궤적을 조사하여 횡방향 이동 특성을 분석하였다. 조사 결과에서 좌우 바퀴 위치는 서로 다른 분포형태를 보였으며, 포장 설계에 적용할 경우 좌측바퀴에 의하여 얻어진 분포의 특성치가 포장에 미치는 영향이 더 크기 때문에 좌측바퀴의 특성치를 적용하는 것이 합리적인 것으로 나타났다. 좌측바퀴 위치의 평균값은 좌측차선을 기준으로 할 때, 승용 승합차량인 경우 3.25m차로 폭에서 59.5cm, 3.5m일 경우 80.7cm에 위치하였고, 화물차량일 경우 각각 58.4cm와 73.6cm인 것으로 나타났다. 차량 축수에 따른 구분에서 2축 차량의 경우 차로 폭에 따라서 60.7cm와 79.1cm 이고, 3축이상일 경우 44.5cm 및 69.2cm 인 것으로 나타났다. 결국, 바퀴의 중심위치는 차로 폭에 따라 다르며, 그 차는 차로 폭의 차이에 기인하는 것으로 판단된다.