IA: US-218 exit 96

[rickmastfan67]

0(380) -> 96

IA-27 could be changed to '96(218)' there as well, or stay as-is, your choice on it.

[Highway63]

Northbound 218 has Exit 96.

But usually, if there's an exit number for the route with it's mileage, that should take priority.

Which way is it supposed to be here?

Southbound 218 still sees Exit 0, so having all three routes refer to I-380 Exit 0 unifies them in that way.

[rickmastfan67]

But usually, if there's an exit number for the route with it's mileage, that should take priority.

Which way is it supposed to be here?

If the route has it's own exit numbers, they gain priority at interchanges like this if they're posted.

Look @ NC I-840 for an example.  It has it's own exit numbering scheme, but also shares a segment of roadway with I-73.  On that shared segment, it uses I-73's numbering.  Going NB, it sees I-73's Exit #107, but we use I-840's exit number for that interchange, which is #3, since it's posted going 'SB'.  If they had instead used I-73's number for the exit that's going SB on I-840, then we would have used the '107(73)' label instead.

We pretty much do that everywhere when another route joins another via freeway connections.