NB: NB134

[bhemphill]

In Campbellton, the route is shown as going down Subway Street to get from Roseberry Street to Water Street, but Andrew Street is where it is signed to get between them.  The turn isn't signed on westbound Water, but is signed on Andrew coming from the info center and the turns are signed on Roseberry and Andrew for both directions.  So it is just the one missing turn sign as of 9/16/2017.  Travelers going east on Roseberry are sent to Quebec via Andrew St as well.  I assume this is because trucks and RVs should not attempt to go under the low railroad bridge (3.6 meters, 11.81 feet) on Subway St.

[yakra]

The shapefiles agree with your findings. The change occurred between the 4.0 & 5.0 revisions, dated 2013-11-04 & 2014-08-04 respectively.

Travelers going east on Roseberry are sent to Quebec via Andrew St as well.

I checked this out, decided it must be a low clearance railroad underpass...

I assume this is because trucks and RVs should not attempt to go under the low railroad bridge (3.6 meters, 11.81 feet) on Subway St.

...and then read the rest of your post.

I've relocated NB134:
https://github.com/TravelMapping/HighwayData/pull/1622