There is a dead image in this answer: Interpolation Splines of Bounded Curvature. We cannot expect the picture from the OP here (it's Bill Thurston's post).

I did not find the image in Wayback Machine snapshot. (I am not sure whether dropbox links are saved there at all.)

Is there some reasonable idea what else could be tried to recover the image? (Since the question has been bumped, I tried to look what other improvements can be done and correcting the image - or other dead links - is something which immediately catches the eye.)

It seems that many posts by the same user contain links to images which are no longer working. (I noticed the post mentioned above simply because it has been bumped.)