It definitely depends on location and era. Pasco had some old sidewalks with roughly 30 inch squares, two-across, for a 5 foot walk. They also had some much newer ones, in the 1970s, well over five feet across, with single squares. Ashland, KY, has some walks, of various ages, only about 30 inches wide, so a single strip of 3/16 would work for them.