With AutoCAD 2014, the ARC command has a simple-but-needed improvement. By default in AutoCAD, arcs are created counter clockwise. With 2014 you can control the creation of arcs to be clockwise or counter clockwise by simply holding the CTRL button.
See below for a more detailed look:
Simply opening the Arc tool’s flyout, there isn’t any obvious, visible change.
The direction that arcs are created are controlled in the UNITS dialog box
Although the new ARC direction option is available in all of the various arc tools, the most practical and obvious uses of the new ARC direction option are found in the ARC options shown below.
In the picture below, the upper arc that is being created shows the default ARC direction. The lower arc shows the new ARC direction option by hold the CTRL button during the command