This article breaks down the naming convention ALDOT used for Route ID fields in Numetric.
The route ID is represented by a 12-character ID.
Route Type
IN = Interstate
AL = State
IV = Off-System
RP = Ramp
NC = New Construction
Route Number
The route number consists of six digits.
Direction
0 = Inventory
1 = Non-inventory
County
000 = On-system
Off-System will have a 3-digit County FIPS number