Effect of Spiral Length on Driving Characteristics in Curves on Two-lane Highway

Abstract:

Based on driving simulation experiments， the speed and lateral offset data of 15 drivers in 72 curve sections with the radius of 100?500 m were collected， and the effects of spiral length on vehicle speed and trajectory on two-lane highway were analyzed. The results show that under the condition of a certain radius， with the increase of spiral length， the speed difference is on the rise， while the speed gradient is on the decline. With the increase of spiral length， the fluctuation amplitude of vehicle trajectory increases， while the fluctuation frequency of vehicle trajectory decreases. When the radius is 100 m， the local curvature of vehicle trajectory will increase if the spiral is too short. For the curves with the radius of 200 m， the local curvature of vehicle trajectory will increase if the spiral is too long or too short. For the curves with the radius of 300 m or more， the length of spiral is positively related to the maximum local curvature of driving trajectory.

Key words:road geometric design;length of spiral;driving simulation;speed consistency;driving trajectory