Regulatory signs
HOV Lane sign
Only vehicles meeting the occupancy number shown, along with buses, motorcycles and other exempt vehicles, may use this lane.
- Tall rectangle
- White
- MUTCD R3-10
Shape and background first
Federal designation R3-10 in the MUTCD, the national standard every state signs to. Marks the leftmost lane on urban freeways and expressways, often paired with a diamond symbol painted directly on the pavement.
What the MUTCD specifies
Designation: R3-10
MUTCD Section 2G.04
Conventional road size: 30 x 42 in
Standard: Use an occupancy definition sign when an agency chooses to state the minimum number of occupants for an HOV lane.
Source: Federal Highway Administration, MUTCD 11th Edition (December 2023), Part 2, Table 2G-1; Section 2G.04, verified 2026-09-26.
How states handle it
The occupancy minimum is not uniform. Some corridors require only two people while others, especially around major cities during peak hours, require three or more.
What the test wants you to know
The mistake people make
The count includes the driver, so a 2+ sign means two people total in the car, not two extra passengers. Check the time plaque underneath before assuming the restriction runs all day, since many HOV lanes open to everyone outside of rush hour.
