Abstract: As unbalanced turning of traffic exists in the big cities, the implementation effect of variable lane is evaluated. The intersection of Wener Road and Jiaogong Road in Hangzhou was used as research object. Based on theoretical analysis of mechanism of variable lane, the paper evaluated the effect of variable lane before and after the implementation. Saturation, delays, queue length, number of stops was selected as evaluation indicators. The quantitative evaluation before and after the function change of variable lane proves the validity of variable lane referred to unbalanced turning traffic.