Usually; under normal circumstances — used to indicate what typically happens or is the case.
通常なら朝7時に出発するが、今日は渋滞で遅れた。
I usually leave at 7 a.m., but today I was delayed by traffic.
通常ならこの手続きに一週間かかります。
Normally, this procedure takes a week.
通常なら無料で使える機能だが、今回は例外だ。
This feature is usually free to use, but this time it's an exception.