Section 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.