Vehicle equipment, inspection and registration

Key points

1. Vehicles need a safety inspection at least once a year; ambulances every 6 months, and new vehicles not until 2 years after their initial inspection.

   Source: Handbook p. 18

   “at least once a year, except that ambulances must be inspected once every six months, and new vehicles do not need to be inspected until two years after their initial inspection”
   Hawaii Driver's Manual, Handbook p. 18

2. A red light showing from the front, or a blue light visible outside the vehicle, is illegal except on emergency vehicles.

   Source: Handbook p. 18

   “A red light showing from the front, or a blue light visible outside of the vehicle, except on authorized emergency vehicles;”
   Hawaii Driver's Manual, Handbook p. 18

3. A bell, exhaust whistle or siren is also prohibited except on emergency vehicles.

   Source: Handbook p. 18

   “A bell, exhaust whistle or siren, except on authorized emergency vehicles;”
   Hawaii Driver's Manual, Handbook p. 18

4. All front and back seat occupants must wear seat belts, and children under 4 must be in a child restraint.

   Source: Handbook p. 20

   “All front and back seat occupants are required by law (291-11.6, HRS) to use seat belts. Children under age 4 must be in a child restraint;”
   Hawaii Driver's Manual, Handbook p. 20

5. Replace tires with less than 1/16 inch of tread.

   Source: Handbook p. 20

   “Replace tires that have less than 1/16 inch of tire tread.”
   Hawaii Driver's Manual, Handbook p. 20

6. Power steering should have no more than 2 inches of free play, or 3 inches without power steering.

   Source: Handbook p. 20

   “There should be no more than two inches of free play in the steering wheel, if you have power steering (check with the motor running); or 3 inches, if you do not have power steering.”
   Hawaii Driver's Manual, Handbook p. 20

7. If your address changes, notify the appropriate county agency within 30 days.

   Source: Handbook p. 21

   “must, within thirty (30) days after the change, notify the appropriate county agency,”
   Hawaii Driver's Manual, Handbook p. 21

8. Motorcycles, trailers and semi-trailers show a rear plate; all other vehicles need plates on both the front and rear.

   Source: Handbook p. 23

   “Motorcycles, trailers and semi-trailers must display a license plate on the rear; all other vehicles must display a license plate on both the front and rear.”
   Hawaii Driver's Manual, Handbook p. 23

Numbers to know

3 questions from the Hawaii practice test

1. 1. When does Hawaii's manual say to replace tires?

   1. When tread is under 1/2 inch
   2. Every two years regardless
   3. When tread is less than 1/16 inch
   4. Only after a blowout
   Show answer

   When tread is less than 1/16 inch. Replace tires that have less than 1/16 inch of tread, and check that the vehicle does not pull to either side under braking; a simple brake test is to apply the brakes rather hard at 4 to 8 mph in a safe place. Proper inflation extends tire life and improves handling, and the manual says good tread depth helps prevent hydroplaning, which can begin at 35 mph, because worn or bald tires hydroplane at lower speeds.

2. 2. A new vehicle is inspected on the date it is first sold in Hawaii. When is its next safety inspection due?

   1. Six months after that initial inspection
   2. One year after that initial inspection
   3. Five years after that initial inspection
   4. Two years after that initial inspection
   Show answer

   Two years after that initial inspection. New vehicles do not need to be inspected again until two years after their initial inspection on the date they are first sold. Six months is the inspection interval for ambulances. One year is the normal interval for other vehicles once the new vehicle period is over. Five years is not a figure in the manual. After the first two years, the yearly inspection rule applies.

3. 3. Which equipment is prohibited on a Hawaii vehicle that is not an authorized emergency vehicle?

   1. A bell, exhaust whistle or siren, a front red or blue light, and a muffler cutout or bypass
   2. Fog lights
   3. A backup camera
   4. A roof rack
   Show answer

   A bell, exhaust whistle or siren, a front red or blue light, and a muffler cutout or bypass. Vehicles other than authorized emergency vehicles may not have a red light showing to the front or a blue light visible outside the vehicle, a bell, exhaust whistle or siren, or a muffler cutout, bypass, or muffler louder than original equipment. The bell, whistle, siren and front red or blue light are allowed only on authorized emergency vehicles. If an ordinary vehicle carries any of these items, remove them before driving it on the highway; fog lights, cameras and roof racks are not on the list.

Source: the Hawaii Driver's Manual, Chapter II: Vehicle Equipment and Inspection. This lesson is a plain English summary, not the law itself; where it differs, the manual and the statute govern. Last checked 2026-09-27.