Here’s a really useful new feature in Civil 3D 2017, namely “Cleaned up corners in Corridor Modelling”. This is great, mainly because you don’t have to do anything at all! It just works. When you have anything that has angled corners, like a Pavement on a turning area, there has always been a bit of work required to clean up the corners. For example, here in AutoCAD Civil 3D 2016 (figure 1) when I model the pavement it cuts the corners off. You can see from the inset picture (figure 2), how the assemblies are applied in corridor.
This was easily overcome by simply applying a small radius curve to the alignment (figure 3) and then set a target for the pavement to reach. I usually just draw a 2d polyline (figure 4).
Well, now in 2017 you don’t have to do anything. It just works on squared corners as you would want it to (figure 5 and 6).
Have fun saving time with your squared edges :)