Here's a shot of the longest road we managed to make in this particular game of
Carcassonne. It starts at a crossroads in the middle left of the picture and carries across 16 tiles to the city at the middle right of picture.
One of the things that we like about Carcassonne is the infinite number of play variations you can make to change the game. One of the ones we play with all the time involves the tile somewhere near the middle of the picture (the 9th tile in the road) which contains two city parts seperated by a road intersection.
The rules say that this intersection ends a road just like any other intersection. However, visually it looks as if the road does not stop at all, unlike other crossroads in the game. So a variation that we play with says that that particular piece is a regular road segment and not an intersection.
Of course, near the end of the game, if the person who is holding The Robber Baron is losing, they start a petition that that piece does in fact count as an intersection, to get more points for completed roads.