Minimum sizes
- Conventional road
- 24" × 30"
- Freeway or expressway
- 36" × 48"
- Minimum
- —
MUTCD 11th Ed, Table 6G-1
Placement by road type
Distance from the transition to the first sign in a series, per Table 6B-1.
- Urban (low speed)
- 100 ft
- Urban (high speed)
- 350 ft
- Rural
- 500 ft
- Expressway / Freeway
- 1000 ft