Loops are roads that you can enter, and without reversing course, end up at the same place you started.
An important Map Editor rule is: ''' a road segment must ''not '' start and end on the same junction node '''.
this rule is not followed, the routing server will have difficulty in providing routes into and out of the loop. Any loop broken into two segments by a junction will not have this problem.
Hopefully there will be another roadway along the loop road which you can map, which will break the loop into two pieces. If there are no interruptions to the loop and the entire loop is represented by one road segment that connects with itself, we must [[Map Editing Quick-start Guide#Splitting a segment|insert a superfluous junction node]] along the loop segment. The specific location does not matter, but most people put it near the half-way point of the segment.
Jct loop bulb.png]] [[File: Jct loop square. png]]
'''NOTE:''' It is very easy for an editor to find the extra junction node, assume it is truly superfluous, and delete it! This problem is magnified if the loop road is large or shaped so it is not obvious that it is a loop. One solution is to identify a path or driveway branching from the loop road and add it to the map, forcing a 3-way junction that would be less likely to be deleted.
'''NOTE:''' The Map Editor may be resistant in editing a loop that does not already follow the rule that it must be broken in two. If you run into saving errors, try one of the following approaches: