This article breaks down the naming convention UDOT used for Route ID fields in Numetric.
Example Route ID: 0015PM27604
Digits 1-4: Route number
0001-0999 = state routes
1000+ = federal aid routes
Character 5: Direction
P = Positive
N = Negative
Character 6: Roadway type
M = Mainline
R = Ramp
C = Collector
If Character 6 = M, the Route ID ends there.
If Character 6 = R or C:
Digits 7-9: Exit number associated with the ramp or collector (approximately the milepoint)
Digits 10-11: Ramp number
Typically numbered clockwise, with exceptions that vary by location