Hawaii Revised Statutes Division 1. Government § 291C-39

The department of transportation, after consultation with the counties, shall adopt rules pursuant to chapter 91 prescribing uniform standards and specifications for all official traffic control devices installed pursuant to this chapter, including stop signs, yield signs, speed limit signs, railroad warning approach signs, street name signs, crossing signs, any lines or markings on a roadway, and any other sign or marking required or authorized by the Federal Highway Administration's Manual on Uniform Traffic Control Devices, as amended.