I know a guy who does a bunch of DCs. He habitually rides a serpentine line which I have watched multiple times.

Figured out that it was about 5" wide based on weaving back & forth over the fog line- most folks will weave no more than the width of the line-

and the length of the wave about a bike length for each half.

Anyway, laid this out with string to calculate the additional distance vs a pretty straight line.

Over a mile extra on a DC, if I recall correctly.