Ideally, a roadway should be continuous with junctions only appearing when other roads or ramps intersect. Unfortunately, when the original Tiger maps were loaded, junctions were placed at every location where two roads appeared to cross. Since an overpass may 'appear' to intersect with a freeway from a two dimensional view a lot of unneeded junctions were added to the map. Generally unnecessary junctions are not harmful, but they are better to be removed if truly unnecessary.
Are any two-segment junctions ever necessary?
Sometimes there are reasons for junctions with only two segments. These include:
- Loop roads. A single segment cannot loop back upon itself, so a junction is required to create two separate segments. It does not matter where the junctions is located, so long as each segment meets the minimum segment length.
- Road, city, or state name change. There are times when a road, city, or state name will change with no other intersecting road at that point. A junction is added to enable each side of the junction to have a different name.
Unnecessary junctions defined
If any of the above criteria are not present, then a two-segment junction is unnecessary and can be removed.
Finding unnecessary junctions
When selecting a segment the two ends are highlighted. If each end of that segment does not have at least two other segments connecting to the end, it may be an unnecessary junction. Be sure to review the criteria above before removing it.
How best to remove a junction
After reviewing the criteria above to be sure the junction is not necessary, when you select the junction in question, if you see the trash can icon in the upper right corner then you can click the trash can to remove the junction.
If the trash can icon does not appear, it means the junction separates two segments that are not identical. Possibly the road, city, or state name is different. It also may indicate one of the connected segments are locked above your editing rank. Last, the segments may have different routing directions, so check them to be sure they are set correctly.