§ 1622. Speed limits on county roads and town highways. The department of transportation upon the request of the county superintendent of highways of a county and the town board of the town or towns affected with respect to county roads and town highways in such town or towns outside of cities or villages, may by order, rule or regulation:

1. Establish maximum speed limits at which vehicles may proceed on or along such highways higher or lower than the fifty-five miles per hour statutory maximum speed limit. No such limit shall be established at less than twenty-five miles per hour, except that school speed limits may be established at not less than fifteen miles per hour, for a distance not to exceed one thousand three hundred twenty feet, on a highway passing a school building, entrance or exit of a school abutting on the highway.

2. Establish maximum speed limits at which vehicles may proceed on or along all such highways lying within an area or areas as designated by a description of the boundaries of such area or areas submitted by the county superintendent of highways of a county and the town board of the town or towns affected lower than fifty-five miles per hour statutory maximum speed limit. No such limit shall be established at less than thirty miles per hour.