Wis. Stat. § 82.18: Width of highways.

Except as otherwise provided in this chapter, highways laid out under this chapter shall be laid out at least 66 feet wide unless, in the town board’s discretion, that width is impractical. If the town board determines that a 66-foot width is impractical, the width shall be determined by the town board but shall be at least 49.5 feet in width. When no width is specified in the highway order, the highway shall be 66 feet wide.