Dynamic markers indicate start and end points along reference shapes.
For example, markers might indicate the portion of a road along which a series of lamp columns will be placed, or the portion of a road to which a swept object might be applied.
In viewports, marker objects appear as wireframe cubes. A green cube indicates the start point, and a red cube indicates the end point (you can change these default colors on the Civil View Preferences panel). To change marker values, you can drag the cubes along the reference shape.
The Start Marker value is constrained to prevent it from having a greater value than the end marker. The End Marker the value is always at least one unit greater than the current Start Marker value.
In a dialog, you can enter a marker value directly, or drag the spinner control arrows up or down.
key while dragging the spinner moves the marker at a faster rate.
+N. 3ds Max Design evaluates the expression you enter, and displays the result in the Result field. Clicking Paste then replaces the spinner value with the result of the calculation. Clicking Cancel exits the Expression Evaluator.