There's actually a hidden
+PA981_S point in the file, just south of PA31. Grade-separated crossing; no interchange. Checking HistoricAerials, there doesn't appear to have ever been an actual connection here. I bet what happened is that Tim included it accidentally when first drafting the PA US routes, and later, upon realizing his mistake, found that the point was in use on CHM, so just hid it in place rather than mess with someone's list file.
PA981_N never got changed.
In any case, this point is no longer in use on TM, and can be safely removed, and
PA981_N safely renamed.
https://github.com/TravelMapping/HighwayData/pull/2150