Using the Maplex Label Engine to set line label orientation allows you to place labels so they align with the lines of latitude of a map's projection. It also allows you to place labels so they follow the digitized direction of features. This is useful for placing one-way arrow symbols for streets.
Orienting line labels to graticules
You can control how line labels are oriented on the map. If you choose a horizontal placement position and your map is in projected space, you can choose to align the labels with the latitude graticules. There are four graticule alignment types to choose from:
- Straight (no flip)
- Curved (no flip)
The Straight and Curved options place the label in alignment with the graticule and orient it to the page. The Straight (no flip) and Curved (no flip) options allow the label to be drawn upside down to align with the graticule.
The image below shows the line label oriented to the graticules.
Aligning labels with line direction
By default, labels are placed in top-down and left-to-right readable positions. Occasionally, you may need to place labels in the same direction as the line features. In these cases, you can choose to align labels with the direction of the lines. This is useful for placing flow symbols on lines, such as the one-way arrows on a street map or the water flow direction on a hydrography map.
The image below shows the arrow label oriented to the line direction. This is used for showing the flow direction of the river.