HRS §291C-8
County police can enforce traffic laws on all public roads
This section says that county police officers have the power to enforce the traffic rules in this chapter on any street, road, or highway owned by the federal, state, or county government. It does not create new rules or penalties, just clarifies who can enforce them.
counties
The statute, as written — County police officer authority
Each county police officer may enforce this chapter for any violation of this chapter that occurs on any federal, state, or county street, roadway, or highway.
LawTrove is not legal advice. The summary above is a computer-generated restatement — the authoritative text is the official version linked above.