Speed Behavior of Passenger Car on Helical Ramps and Helical Bridges in Mountain Riverside City

摘要

Helix alignment can allow for a rapid change in road elevation in size-constrained spaces, and it is becoming increasingly popular in interchange design throughout the world. However, driving patterns and vehicle operating characteristics have not been clearly defined on helical ramps. This work conducted field driving tests on four helical ramps located in Chongqing, China. The trajectory, speed, and acceleration of vehicles under normal driving conditions were collected. Thus speed characteristics and speed patterns on helical ramps, as well as their affecting factors, were obtained and analyzed. The findings in this study can provide basic data referencing for designers and engineers, to help them understand how a multilayered helical ramp works, thus to essentially improve the safety level of helix ramps. Moreover, our findings allow bridge designers to understand whether the actual vehicle operating conditions acted in accordance with their expected design requirements, i.e., whether the expected design requirements are achieved.