In the first picture (on a side road near Carlisle) there does not appear to be any pavement changes or other indicators (of course this border is a UK internal border).

In the second picture there appears to be a pavement and curbing change.
No pavement change noted here either--the same location as the first picture above looking the other direction. At this point, the border is in a stream.
An old bridge over the border stream. The new bridge parallel to the old one with the stream.

 
Another bridge over a border stream. Looking into England from Scotland in both pictures. Second picture shows a slight pavement change. There are no indicators at this point of an internal boundary.