This Reddit comment warns:
Your options of getting to Hana from Wailea are:
- Drive through Kihei to Paia to Hana (this is the typical route with the best road)
- Drive through Kihei then go up Haleakala Highway passing Makawao/Pukalani/Kula and just keep going til Hana. This road eventually gets a bit rough and sometimes closes. [I bolded.] Some car rental companies may ban you from going on this unimproved road.
Which road is being referred? Routes 37, 31, and/or 360?
Is there a website that indicates whether Southern Road to Hana (via keokea) is closed on any given day? How can I know this before leaving my hotel, without trial and error?