- 學位論文
考量猶豫區間與上游車輛行為之號誌時差設計
Signal Offset Design Based on Upstream Vehicle Behavior and Dilemma Zones
摘要
號誌路口事故層出不窮，事故率高有一主要原因是黃燈亮起時，駕駛在決定是否通過路口而引發猶豫不決的問題，其中第II型猶豫區間正是現今影響路口安全的重要因素。然而，過去號誌設計的相關研究大多著重於車流續進效率而未考慮路口安全，當前的續進設計甚至導致駕駛有搶快通過路口的行為。因此，本研究提出一個優先考慮猶豫區間安全的控制架構，透過調整號誌時差設計以減少猶豫區間以及急加速、急減速之車輛數，目標為減少猶豫區間對交通安全所造成的危險，同時將車流效率納入考量，使模型能得出更為安全、效率的號誌控制決策。 本研究利用實地調查資料分析號誌轉換期間的駕駛行為變化，並繪製車流速度軌跡圖用於猶豫區間號誌控制之建構。結果顯示在號誌變化過程中，車流速度會有明顯的變化，且會引起車輛的急加速和急減速行為。為了使模型架構能於實務上應用，本研究透過SUMO模擬不同的情境，經模擬後不僅能應用於不同號誌週期、車流量的環境，亦能針對加入機車的混合車流環境進行最佳的號誌時差設計，對於減少猶豫區間車輛數以及急加速、急減速之行為相較於當前情形皆有所改善。特別是在號誌短週期的情境下，對於減少車流停等時間的現象更為顯著。模擬分析結果亦顯示侵略型駕駛可能會影響車輛在通過路口前的跟車行為，使整體車流速度下降；此外，提升上游路口各方向的車流量之準確性能使最佳號誌設計更具可靠性。本研究之猶豫區間號誌控制架構可作為交通號誌規劃人員於號誌時差設計、猶豫區間保護方法的參考，使現行之號誌路口兼具效率與安全，並為智慧交通的長期規劃有所貢獻。
並列摘要
The number of accidents at signalized intersections is continuing increasing. One of the major reasons for the high accident rate is the indecision situation caused by drivers deciding whether to run through the intersection when the yellow light is on. The Type II Dilemma Zone (DZ) is an essential factor affecting intersection safety nowadays. However, most studies on signal design in the past focus more on the efficiency of traffic progression but incorporate less consideration of intersection safety. The progression band even leads to the situation that drivers rush through the intersection. Hence, this study proposes a control framework that prioritizes the safety regarding the dilemma zone, seeking to reduce the Numbers of Vehicles in the Dilemma Zone (NVDZ), rapid acceleration and deceleration adjusting the offset design of the signal. The ultimate goal is to mitigate the risk of DZ to traffic safety. Meanwhile, the efficiency of traffic flow is taken into consideration, so the model can come up with safer and more efficient signal control decisions. The framework is developed based on the field survey data to estimate the speed trajectory of the traffic flow, which reflects the change of vehicle behavior upon signal switch, and thereupon to minimize DZ hazards. The results indicate a significant change in the traffic speed during the signal switch, and it can cause rapid acceleration and deceleration of individual vehicles. In order to make the model framework applicable in practice, this study simulates different scenarios by SUMO, which can be adopted to signal offset design, considering not only the environment with different signal cycles and traffic flow volumes, but also the mixed traffic flow environment with mopeds. The reduction of NVDZ, rapid acceleration and deceleration can be improved compared with the current situation. Especially in the short-cycle case, the waiting time caused by signal control can be more effectively contained. The simulation results also display that aggressive driving may affect the behavior of following vehicles before they run through the intersection, resulting in a decrease in overall traffic speed. Moreover, improving the accuracy of traffic flow in each direction at upstream intersections increases the reliability of the desired signal design. The DZ signal control framework in this study can be used as a reference for traffic signal planners in the design of signal offsets and DZ protection measures, making the existing signalized intersections more efficient and safer, thereby contributing to the long-term planning of intelligent transportation.