This wiki explains the Add Station Equation tool.
The "Add Station Equation" tool is used to define a station equation at a designated location on the alignment. Multiple station equations can be added to an element, but that should be added in order from the beginning to end of element.
Steps to add station equation :
1. Select Geometry > Horizontal > Modify > Add Station Equation.
2. Follow the heads-up prompts. Locate the alignment.
3. Locate the Back Station and give the required value for back station.
4. Locate the Ahead Station. You must specify a name, for example, a13+00.
The Station Equations can be removed through Project Explorer.