In order to determine the influence of the radius of the spiral tunnel on the vehicle's operation speed and trajectory deviation at the design stage, and provide an improvement basis for reducing the risk of driving the spiral tunnel, based on the existing design parameters of the spiral tunnel in the mountainous highway and the surrounding terrain conditions, according to the difference in sight distance between left and right direction , and the left-downhill, left-uphill, right-uphill, and right-downhill driving simulation scenarios are constructed. Based on the 3D simulation cockpit and UC-winroad software, got the corresponding driving speed and trajectory offset data under different working conditions, and the influence of spiral tunnel radius on vehicle operating characteristics under different working conditions were obtained through SPSS multiple nonlinear regression analysis. The research results show that as the radius increases, the speed variation coefficient gradually increases, and the vehicle

Spiral tunnel, Driving simulation, Speed variation coefficient, Trajectory offset, SPSS regression