Stability analysis of freeway ramp traffic flow based on floating vehicle data

Type A trumpet interchanges are a common form of interchange, facilitating the transfer of traffic between different routes. Frequent behaviors such as acceleration, deceleration, overtaking, and lane changing occur here, often leading to greater instability in traffic flow, making these areas prone to accidents. The article collects high-frequency trajectory point data of logistics trucks to analyze ramp operation characteristics, accurately reflecting the driving behavior of drivers. Implement the ramp and trajectory data matching using the Haversine model with consideration of buffer zones, selecting parameters such as speed, acceleration, and coefficient of variation to analyze the stability of ramp traffic flow. The research results indicate that the speed variation on Ramp A is relatively stable, while Ramp B experiences significant speed fluctuations in the first half of the minimum radius circular curve, particularly before and after the connection between the exit ramp and the roundabout ramp. Ramp C shows notable speed decreases and acceleration fluctuations.