The RCOC method uses the 2025 MMUTCD for device selection, advisory-speed plaques, chevron spacing, delineator spacing, and advance-warning placement. The local/primary classification changes only the W1-8 chevron size.
| RCOC classification | Chevron size (width × height) |
|---|---|
| Local road | 18 × 24 inches |
| Primary road | 24 × 30 inches |
Source of sizing practice: RCOC local/primary dimensions supplied by the calculator owner. This page records that supplied practice; it is not a published RCOC standard or an MMUTCD sizing table.
RCOC mode fixes the roadway type to conventional road. Select Local or Primary separately to obtain a chevron size; the MMUTCD functional class remains a separate input for device selection. Other sign types retain the MMUTCD basis; this calculator reports dimensions for chevrons only.