PURPOSES : In the case of a turning maneuver at an at-grade intersection or changing the driving path, the trajectory of a vehicle with a long body, such as a large bus or an articulated bus, should be analyzed from the perspective of road design. In this study, an articulated bus was selected to analyze the off-tracking, swept path width, and lane encroach hment for vehicle turning.
METHODS : In this study, four scenarios were developed for right- and U-turn situations. For the right-turn situation, cases were divided into radii of 15 m (Scenario 1) and 40 m (Scenario 2). For the U-turn situation, the cases were analyzed based on a U-turn after stopping at the stop line (Scenario 3) and without stopping at the stop line for the U-turn (Scenario 4). Each scenario was examined at 5° (Right-turn) and 10° (U-turn) angles to analyze the off-tracking, swept path width, and lane encroachment. In addition, four Global Positioning System (GPS) antennas were installed on top of the articulated bus to obtain the driving trajectory of the vehicle. GPS locational reference points were marked on the testing ground to improve positioning accuracy.
RESULTS : As a result of the right-turn analysis at an intersection radius of 15 m (Scenario 1), the average off-tracking per angle was 1.04 m, the average swept path width was 3.89 m, and the lane encroachments occurred at an angle of 65° to 70°. For the right-turn analysis at an intersection radius of 40 m (Scenario 2), the average off-tracking per angle was 3.71 m, and the average swept path width was 3.31 m. Unlike the results for the 15-m radius, no lane encroachment was found. Furthermore, the averages of the off-tracking in the at-grade intersection U-turn situation were 2.65 m (Scenario 3) and 2.54 m (Scenario 4), and the average swept path width was 6.15 m.
CONCLUSIONS : The required driving width when an articulated bus performs a turning maneuver at an at-grade intersection was analyzed, revealing the implications that must be considered for busway design.

ABSTRACT
1. 서론
2. 분석 개요
3. 분석 결과
    3.1. 교차로 우회전(시나리오 1, 시나리오 2)
    3.2. 교차로 유턴(시나리오 3, 시나리오 4)
4. 결론 및 향후 연구 과제
REFERENCES

• 박재홍(한국건설기술연구원 도로교통연구본부 수석연구원) | Park Jaehong
• 윤천주(한국건설기술연구원 도로교통연구본부 수석연구원) | Yoon Chunjoo
• 노민형(한국건설기술연구원 도로교통연구본부 박사후연구원) | No Min Hyung
• 성정곤(한국건설기술연구원 도로교통연구본부 선임연구위원) | Sung Jung Gon Corresponding Author