Yeah, this will be the third year in a row where the fall HPR race is a 24.
Glenn (HPR track manager) does a fantastic job making sure the on-track part of the race runs smoothly. For the past 24 hour races he shifted the last test day session to be at night too to help teams adjust their lights and get a handle of racing in the dark.
The LED flags work really well, both day and night. The black flagging has been done via an old-fashioned white board.
My team has run in both of the prior 24 hour races at HPR and plan to again in 2022 (though I'd prefer to take a break from midnight to 6AM if I can convince my drivers the sleep will be worth it). Most of our drivers absolutely LOVE driving this track at night.