Class A highways: state and federal highways that have been improved according to the surveys and plans of the State Highway Commission or plans accepted by the County Board. The center line is the center of the pavement or surfacing or, if there is none, the center of the graded roadbed, or the center of the directional separator if the highway is to be paved as a double-divided road.

Class B highways. For county highways that have not been improved according to engineering surveys or plans accepted by the County Board or its agent, the County Highway Committee, the center line is at the midway point between fences or other markers indicating the boundary on opposite sides thereof. For county highways that have been improved according to engineering surveys and plans accepted by the County Board or its agent, the County Highway Committee, the center line is the center of the surfacing or pavement or, if there is none, the center of the graded roadbed.

Class C highways. For Town roads not otherwise classified that have not been improved in accordance with engineering surveys and plans accepted by the County or Town Board, the center line is the midway point between fences or other markers indicating the boundaries of the highway on opposite sides thereof. For Town roads not otherwise classified that have been improved in accordance with engineering surveys and plans accepted by the County or Town Board, the center line is at the center of the surfacing or pavement or, if there is none, the center of the graded roadbed. For roads and streets in platted subdivisions not otherwise classified, the center line is at the midpoint between the right-of-way lines as shown on the recorded plat.

No new building, new sign, or other new structure or part thereof shall be placed between the setback lines established by this chapter and the highway except as provided by this chapter, and no building, sign, or structure or part thereof existing within such setback lines on the effective date of this chapter shall be altered, enlarged, or added to in any way that increases or prolongs the permanency thereof, or be reconstructed in its original existing location after having been destroyed by fire, storm, or other catastrophe to the extent of 50% or more of its last equalized value, except that an existing building, sign or structure which is damaged or destroyed by violent wind, vandalism, fire, flood, ice, snow, mold or infestation may be restored in accordance with the provisions of § 62.23(7)(hc), Wis. Stats.

The following kinds of structures may be placed between the setback line and the highway:

This section shall not be interpreted so as to prohibit the planting and harvesting of field crops, shrubbery, or trees; provided, however, that no building or structure, trees or shrubbery shall be so located, maintained or permitted to grow so that the view across the clear sight triangle, as provided by § 330-92 of this chapter below, shall be obstructed.

Except as otherwise provided, the distance from the center line to the setback line applicable to the various classifications of highways as defined in this article is provided by the following subsections of this section.

Whenever a highway is improved to a classification requiring a greater setback distance than that required by this chapter prior to such improvement, the setback distance shall be that applicable to the later classification.

In cases where the provisions of this section may be interpreted to provide for different setback distances, the greater setback distance shall prevail.

Along highways generally, the setback distances from the center line, at any point, for the respective classes of highways shall be as follows:

Provided, however, that in no case shall the distance of the setback line outside of and from the nearest point on the boundary line of the highway be less than the following: Class A highways, 75 feet; Class B highways, 67 feet; and Class C highways, 42 feet, except that where structures are to be erected between buildings existing at the time of the adoption of this chapter which are located not more than 250 feet apart and having setback lines less than are established by this article, the Board of Appeals may vary this regulation, provided that the Board of Appeals shall establish such conditions as will hold the Town harmless from additional improvement damages which might accrue when and if the highway is improved, and provided, further, that no such variation will permit a setback less than the average setback of the adjacent buildings.

Clear sight triangle established. The clear sight triangle is a triangle formed by the right-of-way lines of two intersecting roadways or railways and a third straight line. The third straight line shall connect with said right-of-way lines at points as follows: