Use the ResizeAllign plugin to correct those parts sticking through one another.
To speed up this process, generate the full circle with Archimedes and gapfill between two sidewalks on opposite sides that are parallel to one another (this will create a part that is perfectly centered).
You can now delete all road segments except for any sequence of three. You’ll use these three to make your corrected piece with ResizeAllign, utilizing the road both left and right to repair the one in the center. The part in the center will be your corrected road, the ones on the left and right only serve to line up the center road’s parts, so they don’t matter and can be deleted afterwards.
After you make the corrections, you can delete the left and right road segment and you should be left with your one properly sized road segment. After that, you can duplicate the segment and rotate it around the centerpoint you made earlier, so each road segment will line up perfectly.
With this process:
-all of your road parts will be of equal length to one another,
-there’s no need to go through the time-consuming process of correcting every single part in the circle with ResizeAllign,
-there’s no need no need to union anything (which is generally poor practice, and can have negative effects on performance and player collision)
I have a guide on this type of curvature here: