by turns

by turns  {adv. phr.}
First one and then another in a regular way; one substituting for or following another according to a repeated plan.
On the drive to Chicago, the three men took the wheel by turns.
The teachers were on duty by turns.
When John had a fever, he felt cold and hot by turns.
Syn.: IN TURN. Compare: TAKE TURNS.
Categories: adverb