321.423  Flashing lights.
  1.  Definitions.  As used in this section, unless the context otherwise requires:
  a.  “Emergency medical care provider” means as defined in section 147A.1.
  b.  “Fire department” means a paid or volunteer fire protection service provided by a benefited fire district under chapter 357B or by a county, municipality or township, or a private corporate organization that has a valid contract to provide fire protection service for a benefited fire district, county, municipality, township or governmental agency.
  c.  “Member” means a person who is a member in good standing of a fire department or a person who is an emergency medical care provider employed by an ambulance, rescue, or first response service.
  2.  Prohibited lights.  A flashing light on or in a motor vehicle is prohibited except as follows:
  a.  On an authorized emergency vehicle.
  b.  On a vehicle as a means of indicating a right or left turn, a mechanical failure, or an emergency stop or intent to stop.
  c.  On a motor vehicle used by a rural mail carrier when stopping or stopped on or near a highway in the process of delivering mail, if such a light is any shade of color between white and amber and if it is mounted as a dome light on the roof of the vehicle.
  d.  On a vehicle being operated under an excess size permit issued under chapter 321E.
  e.  A flashing blue light on a vehicle upon which a blue light is permitted pursuant to subsection 3 of this section.
  f.  A flashing white light, including a flashing headlamp, is permitted on a vehicle pursuant to subsection 7.
  g.  Flashing red and amber warning lights on a school bus as described in section 321.372, and a white flashing strobe light mounted on a school bus as permitted under section 321.373, subsection 7.
  h.  A flashing amber light is permitted on a towing or recovery vehicle, a utility maintenance vehicle, a municipal maintenance vehicle, a highway maintenance vehicle, a construction vehicle, a solid waste or recycling collection service vehicle, or a vehicle operated in accordance with subsection 6 or section 321.398 or 321.453.
  i.  Modulating headlamps in conformance with 
49 C.F.R. §571.108 S7.9.4.
 are permitted on a motorcycle.
  j.  On a vehicle being operated as an escort vehicle for a funeral procession as provided in section 321.324A.
  3.  Blue light.
  a.  A blue light shall not be used on any vehicle except for the following:
  (1)  A vehicle owned or exclusively operated by a fire department.
  (2)  A vehicle authorized by the chief of the fire department if the vehicle is owned by a member of the fire department, the request for authorization is made by the member on forms provided by the department, necessity for authorization is demonstrated in the request, and the member has received emergency vehicle operations training.
  (3)  A vehicle authorized by the chief officer of an emergency medical services agency, if the vehicle is owned by a member of the emergency medical services agency, the request for authorization is made by the member on forms provided by the department, and necessity for authorization to respond to an emergency call or fire alarm under section 321.231C is demonstrated in the request.
  (4)  An authorized emergency vehicle, other than a vehicle described in paragraph “a”, subparagraph (1) or (2).
  (5)  A motor truck, trailer, tractor, truck-mounted snow blower, or motor grader owned by the state or any political subdivision of the state, including any local authority, if the blue light is rear-facing and used in conjunction with amber and white lighting devices or reflectors while the equipment is being used for snow and ice treatment or removal on the public streets or highways.
  b.  A person shall not use only a blue light on a vehicle unless the vehicle meets the requirements of paragraph “a”, subparagraph (1), (2), or (3).
  4.  Expiration of authority.  The authorization shall expire at midnight on the thirty-first day of December five years from the year in which it was issued, or when the vehicle is no longer owned by the member, or when the member has ceased to be an active member of the fire department or of an ambulance, rescue, or first response service, or when the member has used the blue or white light beyond the scope of its authorized use. A person issued an authorization under subsection 3, paragraph “a”, subparagraph (2), shall return the authorization to the fire chief upon expiration or upon a determination by the fire chief or the department that the authorization should be revoked.
  5.  When used.  The certificate of authorization shall be carried at all times with the certificate of registration of the authorized vehicle and the operator of the vehicle shall not illuminate the blue or white light except in any of the following circumstances:
  a.  When the member is en route to the scene of a fire or is responding to an emergency in the line of duty requiring the services of the member.
  b.  When the authorized vehicle is transporting a person requiring emergency care.
  c.  When the authorized vehicle is at the scene of an emergency.
  d.  The use of the blue or white light in or on a private motor vehicle shall be for identification purposes only.
  6.  Amber flashing light.  A farm tractor, farm tractor with towed equipment, self-propelled implement of husbandry, road construction or maintenance vehicle, road grader, or other vehicle principally designed for use off the highway which, when operated on a primary or secondary road, is operated at a speed of thirty-five miles per hour or less, shall be equipped with and display an amber flashing light visible from the rear at any time from sunset to sunrise. If the amber flashing light is obstructed by the towed equipment, the towed equipment shall also be equipped with and display an amber flashing light as required under this subsection. All vehicles specified in this subsection which are manufactured for sale or sold in this state shall be equipped with an amber flashing light in accordance with the standards of the American society of agricultural engineers.
  7.  Flashing white light.
  a.  Except as provided in section 321.373, subsection 7, and subsection 2, paragraphs “c” and “i” of this section, a flashing white light shall only be used on a vehicle in the following circumstances:
  (1)  On a vehicle owned or exclusively operated by an ambulance, rescue, or first response service.
  (2)  On a vehicle authorized by the director of health and human services when all of the following apply:
  (a)  The vehicle is owned by a member of an ambulance, rescue, or first response service.
  (b)  The request for authorization is made by the member on forms provided by the department of health and human services.
  (c)  Necessity for authorization is demonstrated in the request.
  (d)  The head of an ambulance, rescue, or first response service certifies that the member is in good standing and recommends that the authorization be granted.
  (3)  On an authorized emergency vehicle.
  (4)  On a motor truck, trailer, tractor, truck-mounted snow blower, or motor grader owned by the state or any political subdivision of the state, including any local authority, if the white light is rear-facing and used in conjunction with amber and blue lighting devices or reflectors while the equipment is being used for snow and ice treatment or removal on the public streets or highways.
  (5)  On a motor truck or trailer owned and operated by the department equipped with an impact attenuator and audible warning system, if the flashing white light is rear-facing on the audible warning system and used in conjunction with amber lighting devices or reflectors while the motor truck or trailer is being used for slow-moving maintenance operations.
  (6)  On a vehicle or other equipment not owned and operated by the department when used in road work zones on state or local highways as authorized by the department. The department shall adopt rules pursuant to chapter 17A regarding the vehicles or equipment eligible to use a flashing white light under this subparagraph.
  b.  The department of health and human services shall adopt rules to establish issuance standards, including allowing local emergency medical service providers to issue certificates of authorization, and shall adopt rules to establish certificate of authorization revocation procedures.
[C39, §5034.32; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §321.423]
85 Acts, ch 37, §2; 90 Acts, ch 1225, §1 – 7; 91 Acts, ch 131, §2 – 4; 94 Acts, ch 1087, §2; 95 Acts, ch 41, §25; 95 Acts, ch 118, §25; 96 Acts, ch 1034, §21 – 23; 97 Acts, ch 108, §22; 2000 Acts, ch 1045, §2, 3; 2001 Acts, ch 32, §19; 2005 Acts, ch 8, §29 – 31; 2006 Acts, ch 1070, §14; 2010 Acts, ch 1069, §99; 2015 Acts, ch 81, §3, 4; 2017 Acts, ch 84, §3; 2018 Acts, ch 1002, §2, 3; 2018 Acts, ch 1079, §5; 2019 Acts, ch 24, §44; 2021 Acts, ch 97, §2 – 5, 9; 2022 Acts, ch 1089, §2 – 4; 2023 Acts, ch 19, §1063 – 1065
Referred to in §321.1, 321.231C, 321.323A, 321.422, 805.8A(3)(ab)
See also §321.383 
For applicable scheduled fines, see §805.8A, subsection 3
Subsection 7, paragraph a, subparagraph (2), unnumbered paragraph 1 amended
Subsection 7, paragraph a, subparagraph (2), subparagraph division (b) amended
Subsection 7, paragraph b amended