Additional Details
Hawaii route signs
- Big Island highway numbers are 10 to 29
- Maui highway numbers are in the 30 to 39
- Molokai and Lanai highway numbers 40 to 49
- Kauai highway numbers are in the 50-59
- Oahu numbers are 60 to 999 and Interstates.
State highway route numbers have two, three, or four digits. Two-digit routes are assigned to routes in the primary highway system. Secondary state highways get three-digit numbers.
All the state highways on Lanai and Molokai are secondary routes, with three-digit route numbers.
MUTCD Section 2D.10 Route Signs and Auxiliary Signs
Standard:
All numbered highway routes shall be identified by route signs and auxiliary signs.
The signs for each system of numbered highways, which are distinctive in shape and color, shall be used only on that system and the approaches thereto.
Route signs and any auxiliary signs that accompany them shall be retroreflective.
Option:
Route signs and auxiliary signs may be proportionally enlarged where greater legibility is needed.
Support:
Route signs are typically mounted in assemblies with auxiliary signs.