Impact of the connected vehicle environment on tunnel entrance zone

The drastic changes of the space environment at the tunnel entrance can lead to frequent accidents with higher levels. The connected vehicle environment provides drivers with surrounding traffic information and improve their driving behavior by helping them make safe decisions efficiently. As such, this study is to examine the effects of the connected vehicle environment on driving behavior and safety at the tunnel entrance zone. To this end, this research simulates a connected vehicle environment and provides driving aids through the Human-Machine Interface (HMI). Secondly, 40 participants with diverse backgrounds drove the simulator under two different driving conditions: HMI-OFF (traditional driving environment) and HMI-ON (connected vehicle environment). Finally, indicators are selected from speed control, stability and urgency to analyze the impact of the connected vehicle environment on drivers' behaviors and safety at the warning zone and tunnel entrance zone. The results show that in the connected vehicle environment, the drivers' speed control in the warning zone is improved and their deceleration behavior is advanced. The driver's speed control and stability are improved while the danger level of the accident is reduced 100 m ahead of the tunnel entrance. Besides, the driver's speed control and stability have been both improved 300 m after the tunnel entrance. Overall, in the connected vehicle environment, the driver can recognize the tunnel in advance and adjust his driving speed in time to ensure his safety at the tunnel entrance. The results of this study play a critical role in the design and research of warning systems in a connected vehicle environment, and will also guide vehicle manufacturers in designing safety-related functions of automated vehicles. In this research, a connected vehicle environment test platform based on driving simulation technology is constructed and tested in specific tunnel entrance scenarios, which provides a reference for realizing active protection of vehicles at the tunnel entrance.