The HOS Final Rule has been published in the Federal Register.  The link to the Federal Register publication is:
https://www.govinfo.gov/content/pkg/FR-2020-06-01/pdf/2020-11469.pdf.  
 
A copy of the rule can be downloaded here.
 
Final rule is effective September 29, 2020. Petitions for
Reconsideration of this final rule must be submitted to the FMCSA

Administrator no later than July 1, 2020.