NC: I-85 exit number issues

[rickmastfan67]

174 -> 174A
174A -> 174B (or 174)

Fixing this would also require US-15, US-70, & US-501 to have their "I-85(XXX)" labels updated as well.

I know, small issue, but something that needs to be adjusted IMO.  Sadly, will 'break' some people's lists due to '174A' having to be moved.

[mapmikey]

changes made and in the queue