1. (1) This article 4 must be applicable and uniform throughout this state and in all political subdivisions and municipalities. Cities and counties, incorporated cities and towns, and counties shall regulate and enforce all traffic and parking restrictions on streets that are state highways as provided in section 43-2-135 (1)(g), and all local authorities may enact and enforce traffic regulations on other roads and streets within their respective jurisdictions. All such regulations are subject to the following conditions and limitations:

   1. (a) All local authorities may enact, adopt, or enforce traffic regulations which cover the same subject matter as the various sections of this article and such additional regulations as are included in section 42-4-111, except as otherwise stated in paragraphs (c) to (e) of this subsection (1).
   2. (b) All local authorities may, in the manner prescribed in article 16 of title 31, C.R.S., or in article 15 of title 30, C.R.S., adopt by reference all or any part of a model traffic code which embodies the rules of the road and vehicle requirements set forth in this article and such additional regulations as are provided for in section 42-4-111; except that, in the case of state highways, any such additional regulations shall have the approval of the department of transportation.
   3. (c) No local authority shall adopt, enact, or enforce on any street which is a state highway any ordinance, rule, or resolution which alters or changes the meaning of any of the rules of the road or is otherwise in conflict with the provisions of this article. For the purpose of this section, the rules of the road shall be construed to mean any of the regulations on the operation of vehicles set forth in this article which drivers throughout the state are required to obey without the benefit or necessity of official traffic control devices as declared in section 42-4-603 (2).

   4. (d)

      1. (I) Local authorities do not have the power to enact regulations governing:

         1. (A) The driving of a vehicle by a person under the influence of alcohol or of a controlled substance, as defined in section 18-18-102 (5), or under the influence of any other drug to a degree that renders the person incapable of safely operating a vehicle, or by a person whose ability to operate a vehicle is impaired by the consumption of alcohol or by the use of a controlled substance, as defined in section 18-18-102 (5), or any other drug;
         2. (B) The licensing of drivers;
         3. (C) The duties and obligations of persons involved in traffic accidents; and
         4. (D) Vehicle equipment requirements in conflict with the provisions of this article 4.
      2. (II) Local authorities, within their respective jurisdictions, shall enforce the state laws pertaining to the subjects described in subsection (1)(d)(I) of this section, and in every charge of violation the complaint must specify the section of state law under which the charge is made and the state court having jurisdiction.
   5. (e) Pursuant to section 43-2-135 (1)(g), C.R.S., no regulation of a local authority shall apply to or become effective for any streets which are state highways, including any part of the national system of interstate and defense highways, until such regulation has been presented to and approved in writing by the department of transportation; except that such regulations shall become effective on such streets sixty days after receipt for review by the department of transportation if not disapproved in writing by said department during that sixty-day period.
2. (2) The municipal courts have jurisdiction over violations of traffic regulations enacted or adopted by municipalities. However, the provisions of sections 42-4-1701, 42-4-1705, and 42-4-1707 shall not be applicable to municipalities.
3. (3) A person convicted of a violation of a municipal traffic ordinance is not subject to be charged or tried in a state court for the same or a similar offense arising from the same event.

4. (4)

   1. (a) Any municipality, city, county, or city and county located within the program area of the AIR program area as defined in section 42-4-304 may adopt ordinances or resolutions pertaining to the enforcement of the emissions control inspection requirements set forth in section 42-4-310.
   2. (b) An officer coming upon an unattended vehicle in the program area which is in apparent violation of an ordinance or resolution adopted as authorized in paragraph (a) of this subsection (4) may place upon such vehicle a penalty assessment notice indicating the offense and directing the owner or operator of such vehicle to remit the penalty assessment as set forth in such ordinance to the local jurisdiction in whose name the penalty assessment notice was issued.
   3. (c) The aggregate amount of fines, penalties, or forfeitures collected pursuant to ordinances or resolutions adopted as authorized in paragraph (a) of this subsection (4) shall be retained by the local jurisdiction in whose name such penalty notice was issued.
5. (5) The general assembly declares that the adjudication of class A and class B traffic infractions through the county court magistrate system was not intended to create a conflict between the provisions of this article and municipal ordinances covering the same subject matter as this article nor was it intended to require or prohibit the decriminalization of municipal ordinances covering the same subject matter as this article. Municipalities may continue to enforce violations of such ordinances through municipal court even though similar state offenses are enforced through the magistrate system established under this article.

6. (6)

   1. (a) The general assembly hereby finds that the use of automated driving systems will help people who may have difficulty driving, including people who are elderly and people with disabilities, gain access to goods and services essential to daily life. This access requires traveling across and in multiple jurisdictions. Therefore, the regulation of automated driving systems is a matter of statewide concern.
   2. (b) A state agency or a political subdivision of the state shall not adopt or enforce a policy, rule, or ordinance that sets standards for an automated driving system that are different from the standards set for a human driver.

Source: L. 94: Entire title amended with relocations, p. 2233, § 1, effective January 1, 1995. L. 99: IP(1) and (1)(b) amended, p. 367, § 1, effective August 4. L. 2002: (2) amended, p. 1611, § 7, effective January 1, 2004. L. 2012: (1)(d) amended, (HB 12-1311), ch. 281, p. 1632, § 89, effective July 1. L. 2017: (6) added, (SB 17-213), ch. 277, p. 1517, § 3, effective August 9. L. 2019: (2) amended, (HB 19-1147), ch. 178, p. 2033, § 14, effective August 2. L. 2025: IP(1), (1)(d), and (3) amended, (HB 25-1112), ch. 348, p. 1877, 1, effective August 6.

Editor's note: (1) This section is similar to former § 42-4-108 as it existed prior to 1994, and the former § 42-4-110 was relocated to § 42-4-112.

(2) Section 4(2) of chapter 348 (HB 25-1112), Session Laws of Colorado 2025, provides that the act changing this section applies to offenses committed on or after August 6, 2025.

Cross references: (1) For the penalty for class A and class B traffic infractions, see § 42-4-1701 (3)(a)(I).

(2) For the legislative declaration in SB 17-213, see section 1 of chapter 277, Session Laws of Colorado 2017.