Superelevation and changes in superelevation (i.e. crossfall) within an intersection can have a detrimental effect on vehicle stability, particularly for heavy vehicles.
In general, the crossfall adopted for turning roadways where vehicles can turn at moderate speed should desirably not exceed +7% or -3%. For a turn executed at very slow speed (say < 10 km/h), the desirable maximum adverse crossfall (i.e. the vector sum) is -5%.
The diagram below shows how a 3% crossfall and a 3% longitudinal fall can combine to result in a 4.2% adverse crossfall throughout a right turn.