Research on Driving Behavior of Different Length Tunnels Based on Time Domain and Frequency Domain Analysis

The tunnel is a closed, space-tight structure, easy to affect the safety of the driver, and the severity of traffic accidents inside the tunnel is relatively higher. In order to explore the differences in driving behavior in different length tunnel environments on expressway, and promote the tunnel targeted safe operation, 10 experienced drivers are recruited to carry out the real vehicle test in the Zhongnanshan tunnel group of Qinling Mountains. Capture vehicle steering data, speed data, and driver heart rate data using steering wheel goniometer, CAN-OBD, and heart rate monitor. After data pre-processing, the vehicle steering characteristics, speed characteristics and driver heart rate characteristics are analyzed in time domain. Vehicle steering angular velocity, vehicle speed and driver's heart rate signal are converted into the frequency domain by Fourier transform for spectrum analysis. The results show that when the driver is driving inside the tunnel, as the length of the tunnel increases, the speed of the steering angle decreases first and then rises, the vehicle speed is on the downward trend, the heart rate and heart rate growth rate of the driver are on the upward trend. In the meanwhile, the longer the tunnel length, the lower the subjective active participation of the driver is, the worse the vehicle's speed retention capability is, and the heart rate stability also gradually deteriorates. The manual simulation environment in the extra-long tunnel can create psychophysiological stimulation for the driver, relieve the load of long-term driving in the tunnel, and improve the stability of driving performance and driving behavior indicators. The research findings can provide theoretical guidance for developing and improving the safety policy of different length tunnels.