By means of a driving simulator experiment and an accident data analysis, this research focuses on two points: (1) an expected difference in turbulence between major fork configurations that differ in the number of mandatory lane changes for rightmost traffic going to the left-diverging roadway, and (2) an expected difference in driver expectancy between left-diverging roadways of a major fork (that are also small-radius connector roads) that differ in the number of traffic lanes they include.