track day; track meet; track event
A non-competitive driving event where participants drive on a race course for enjoyment or practice, not for racing against others.
I signed up for next month's track day.
At a track day, you can drive the circuit at your own pace.
サーキット走行 refers to the act of driving on a circuit in general, while 走行会 specifically refers to an organized event.
Compound of 走行 (driving, running) and 会 (meeting, gathering).