THE DECELERATION LENGTH OF LEFT-TURN LANE OF FOUR-LANE HIGHWAY BY FIELD OBSERVATION

摘要

In order to make the deceleration length more practical without compromising safety, a new concept left-turn lane design method was produced and was used on a new four-lane highway in Yunnan Province. We observed vehicles speed on a selected left-turn lane set up with the new concept and obtained speed data of normal section and split point. Then we analyzed the data by means of descriptive statistics analysis, the paired-samples T test and ANOVA. The result showed that the length of left-turn lane could be shorter than the specification without compromising comfort and safety. The speed used to determine the deceleration length could be reduced by 15km/h.