Colorado § 42-4-903 - Turning movements and required signals.
Full text of Colorado Colorado Revised Statutes § 42-4-903 — Turning movements and required signals., with citation guidance and answers to common questions.
§ 42-4-903. Turning movements and required signals.
(1) No person shall turn a vehicle at an intersection unless the vehicle is in proper position upon the roadway as required in section 42-4-901, or turn a vehicle to enter a private road or driveway, or otherwise turn a vehicle from a direct course or move right or left upon a roadway unless and until such movement can be made with reasonable safety and then only after giving an appropriate signal in the manner provided in sections 42-4-608 and 42-4-609.
(2) A signal of intention to turn right or left shall be given continuously during not less than the last one hundred feet traveled by the vehicle before turning in urban or metropolitan areas and shall be given continuously for at least two hundred feet on all four-lane highways and other highways where the prima facie or posted speed limit is more than forty miles per hour. Such signals shall be given regardless of existing weather conditions.
(3) No person shall stop or suddenly decrease the speed of a vehicle without first giving an appropriate signal in the manner provided in sections 42-4-608 and 42-4-609 to the driver of any vehicle immediately to the rear when there is opportunity to give such signal.
(4) The signals provided for in section 42-4-608 (2) shall be used to indicate an intention to turn, change lanes, or start from a parked position and shall not be flashed on one side only on a parked or disabled vehicle or flashed as a courtesy or "do pass" signal to operators of other vehicles approaching from the rear.
(5) Any person who violates any provision of this section commits a class A traffic infraction.
Source: L. 94: Entire title amended with relocations, p. 2357, § 1, effective January 1, 1995.
Editor's note: This section is similar to former § 42-4-803 as it existed prior to 1994, and the former § 42-4-903 was relocated to § 42-4-1003.
ANNOTATION
A driver must first signal and then begin moving right or left to change lanes. The phrase "indicate an intention to ... change lanes" means that a person must signal and then change lanes. A person who crosses the line before signaling has violated the statute. People v. Gutierrez, 2020 CO 60, 465 P.3d 577.
A turn signal is not required for navigating roundabouts. A driver need not use a turn signal when entering or exiting a roundabout. People v. McBride, 2020 COA 111, 490 P.3d 810, rev'd on other grounds, 2022 CO 30, 511 P.3d 613.
The violation of this section does not, of itself, impose liability for injuries caused by an automobile, but the person seeking to recover for such injuries must show, not only a violation, but that such was the proximate cause of the damage sustained. Barsch v. Hammond, 110 Colo. 441, 135 P.2d 519 (1943).
Evidence showing violation. Alden v. Watson, 106 Colo. 103, 102 P.2d 479 (1940).
Section relating to parking outside business inapplicable under certain circumstances when signals given. Where the condition of the traffic was such that the truck driver had the right to slow down, and even to stop, prior to making the left-hand turn, provided he gave the statutory signals, § 42-4-803, relating to parking outside of a business or residence, does not apply. Hinkle v. Union Transf. Co., 229 F.2d 403 (10th Cir. 1955).
It is not a reasonable mistake of law to interpret the plain language of this section to conclude that a driver is required to signal continuously for any set distance before changing lanes on a highway and therefore provide reasonable suspicion to justify a traffic stop pursuant to the fourth amendment when the driver did not signal continuously for two hundred feet prior to the lane change. People v. Burnett, 2019 CO 2, 432 P.3d 617.
PART 10
DRIVING - OVERTAKING - PASSING
Cross references: For penalties for class A traffic infractions, see § 42-4-1701 (3)(a)(I).
Source: official Colorado text · Last verified 2026-08-27
Frequently Asked Questions About Colorado § 42-4-903
What does Colorado Revised Statutes § 42-4-903 cover?
Section 42-4-903 ("Turning movements and required signals.") is part of the Colorado Revised Statutes, the codified statutory law of Colorado. It sets out the legal rule or procedure described in the text above. Statutes are amended regularly, so always verify against the official source.
How do I cite Colorado § 42-4-903?
A common citation format is "Colorado Revised Statutes § 42-4-903" (Colorado). Legal writing may require the code abbreviation, section number, and year or edition. Match the style required by your court, professor, or publisher.
Is this the official text of Colorado law?
No. This page is for research and education and may not include the most recent amendments. For official current law, check the Colorado official source linked on this page or consult a licensed Colorado attorney.
How does Colorado § 42-4-903 apply to my situation?
Statutes are interpreted in context, and application depends on your specific facts. Only a licensed attorney in Colorado can advise on how this section applies to you. Contact your state or local bar association for a referral.
Sources & Verification
Not legal advice. Verify against the official source and consult a licensed attorney in Colorado.