I've created this special grid label for clients a few times during many AutoCAD Civil 3D style setups. This is achieved by using a custom label on a predefined marker point within a subassembly or by using a Marked Point subassembly. It is a creative way to leverage a Code Set Styles, useful to make existing or proposed features such as Edge of Pavement and Right of Ways stand out.
Like I said the magic is driven from a Marker Label Style, that draws a line from the bottom and top of the grid and pacing a label there too.
First, you’ll need to know the code that you want to stand out. The use of the subassemblies help file is key here, or if you are using a Marked Point remember the code assigned (I find it useful to use the copy/paste).