AutoCAD 2017 offers powerful new tools for creating and editing centerlines and center marks. You can access the Center Mark and Centerline tools from the Annotate ribbon tab.
The Centerline tool creates centerline geometry of a specified linetype in association with selected lines and polylines. The Center Mark tool creates an associative center mark at the center of a selected circle, arc, or polygonal arc. If you edit the associated objects, the centerlines and center marks update accordingly.
You can modify centerlines and center marks with their grips. A multi-functional grip menu offers additional controls.
You can also use the Properties or Quick Properties palettes to view and edit centerline and center mark properties.
Additional CENTER commands and system variables let you further control the behavior and appearance of centerlines and center marks.
Watch Video below for more information.
Video - AutoCAD 2017 Centerlines and Center Marks