If State law defines my residential streets as public streets (with traffic law jurisdiction), yet the HOA owns the streets, can the HOA still legally

The HOA is generally entitled to enforce the CC&R's and Rules and Regulations on the streets which it owns.  NRS 116.3102(1)(s) states in part that the Association may "[d]irect the removal of vehicles improperly parked on property owned or leased by the association, as authorized pursuant to NRS 487.038, or improperly parked on any road, street, alley or other thoroughfare within the common-interest community in violation of the governing documents." You are correct that there is a limitation under NRS 116.350(1) which provides that where the community is not gated, the Board of the HOA "shall not and the governing documents must not provide for the regulation of any road, street, alley or other thoroughfare the right-of-way of which is accepted by the State or a local government for dedication as a road, street, alley or other thoroughfare for public use."  However the HOA can through its CC&R's set forth rules that regulate even public roads within the Community that "reasonably restrict the parking or storage of recreational vehicles, watercraft, trailers or commercial vehicles in the common-interest community to the extent authorized by law."  Without knowing the nature of the violations which you are encountering relating to your streets appurtentant to your residence, you should consult with counsel to more specifically analyze your situation.