321G.9  Operation on roadways and highways.
  A person shall not operate a snowmobile upon roadways or highways, as defined in section 321.1, except as provided in this chapter.
  1.  A snowmobile shall not be operated at any time within the right-of-way of any interstate highway or freeway within this state. However, a snowmobile may be operated within the right-of-way of an interstate highway or freeway when using an underpass or crossing a bridge located on the interstate highway or freeway if the snowmobile is brought to a complete stop before entering onto the right-of-way and the driver yields the right-of-way to any approaching vehicle on the roadway.
  2.  A snowmobile may make a direct crossing of a street or highway provided all of the following occur:
  a.  The crossing is made at an angle of approximately ninety degrees to the direction of the highway and at a place where no obstruction prevents a quick and safe crossing.
  b.  The snowmobile is brought to a complete stop before crossing the shoulder or main traveled way of the highway.
  c.  The driver yields the right-of-way to all oncoming traffic which constitutes an immediate hazard.
  d.  In crossing a divided highway, the crossing is made only at an intersection of such highway with another public street or highway.
  3.  A snowmobile shall not be operated on public highways under any of the following conditions:
  a.  On the roadway portion of a highway and adjacent shoulder, or at least five feet on either side of the roadway, except as provided in subsection 4.
  b.  On limited access highways and approaches.
  c.  For racing any moving object.
  d.  Abreast with one or more other snowmobiles on a city highway.
  4.  A registered snowmobile may be operated under the following conditions:
  a.  Upon city highways which have not been plowed during the snow season or on such highways as designated by the governing body of a municipality.
  b.  On that portion of county roadways that have not been plowed during the snow season or not maintained or utilized for the operation of conventional two-wheel drive motor vehicles.
  c.  On highways in an emergency during the period of time when and at locations where snow upon the roadway renders travel by conventional motor vehicles impractical.
  d.  On the roadways of that portion of county highways designated by the county board of supervisors for such use during a specified period. The county board of supervisors shall evaluate the traffic conditions on all county highways and designate roadways on which snowmobiles may be operated for the specified period without unduly interfering with or constituting an undue hazard to conventional motor vehicle traffic. Signs warning of the operation of snowmobiles on the roadway shall be placed and maintained on the portions of highway thus designated during the period specified for the operation.
  e.  On the roadway or shoulder when necessary to cross a bridge or culvert, or avoid an obstruction which makes it impossible to travel on the portion of the highway not intended for motor vehicles, if the snowmobile is brought to a complete stop before entering onto the roadway or shoulder and the driver yields the right-of-way to any approaching vehicle on the roadway.
  f.  Snowmobiles shall not be operated on all-terrain vehicle trails except where designated by the controlling authority and the primary all-terrain vehicle trail sponsor.
  5.  The headlight and taillight shall be lighted during the operation on a public highway at any time from sunset to sunrise, and at such other times when conditions such as fog, snow, sleet or rain provide insufficient lighting to render clearly discernible persons and vehicles at a distance of five hundred feet ahead.
  6.  A snowmobile shall not be operated within the right-of-way of a primary highway between the hours of sunset and sunrise except on the right-hand side of the right-of-way and in the same direction as the motor vehicular traffic on the nearest lane of traveled portion of the right-of-way.
[C71, 73, 75, 77, 79, 81, §321G.9]
89 Acts, ch 244, §14 – 21
; 90 Acts, ch 1230, §80
; 92 Acts, ch 1168, §1
; 98 Acts, ch 1073, §9
; 2004 Acts, ch 1132, §10 – 15
; 2012 Acts, ch 1100, §14
; 2015 Acts, ch 38, §1

For applicable scheduled fines, see §805.8B, subsection 2, paragraph b 
Subsection 1 stricken and rewritten