VictimsGuide • Wyoming Crash Liability

Comparative Fault & Crash Liability

Wyoming does not decide a crash simply by asking which driver received a citation or who technically possessed the right-of-way. Fault is allocated among the people and entities whose conduct proximately contributed to the collision and resulting injuries.

The Wyoming 50% Rule A claimant may recover when the claimant's share of total fault is 50% or less. The recovery is reduced by that percentage. If the claimant is more than 50% at fault, recovery is barred.

How Comparative Fault Changes Recovery

0% Claimant fault
100% recovery

25% Claimant fault
75% recovery

50% Claimant fault
50% recovery

51% Claimant fault
Recovery barred

Fault Is Allocated Among All Causative Actors

Wyoming's comparative-fault statute uses the term actor, not merely defendant.

An actor can be a person or entity whose fault proximately contributed to the injury even if that actor is not formally a party to the lawsuit.

Depending on the crash, potential actors may include:

claimant driver
other driver
additional motorist
vehicle owner
employer
commercial operator
road contractor
governmental entity
vehicle manufacturer
other responsible entity

Wyoming Uses Several Liability Each defendant ordinarily answers only for that defendant's proportion of the total fault. That makes identifying every responsible actor and every available insurance policy particularly important.

Right-of-Way Does Not Mean Zero Fault

A driver may possess the legal right-of-way and still have a duty to operate with reasonable care.

Speed, lookout, lane changes, traffic conditions and vehicle control remain relevant.

Bunning v. Romero — 2026

The preferred driver was traveling on a through highway and the other driver failed to yield.

But the preferred driver was also speeding and weaving through traffic. Wyoming courts allocated more than 50% of the fault to him, which barred his recovery.

The right-of-way remained his. It simply did not erase his own causative negligence.

A Traffic Violation Is Part of the Negligence Analysis

Wyoming does not apply a simplistic rule that every traffic-statute violation automatically decides negligence and liability.

Statutory violations can supply important evidence concerning the applicable standard of care, but the analysis still requires breach, proximate causation and comparative fault.

Question	Why It Matters
What traffic rule applied?	Identify the actual statutory duty.
Was it violated?	Determine the underlying conduct rather than relying solely on a citation.
Was there an excuse or unusual circumstance?	Weather, emergency and unexpected roadway conditions may affect the reasonable-care analysis.
Did the conduct cause the crash?	A violation unrelated to the collision does not itself establish crash causation.
What did the other actors contribute?	Wyoming ultimately compares causative fault.

A Traffic Conviction Does Not Decide the Civil Case

Wyoming law provides that evidence of a conviction for a violation of the Wyoming traffic act is not admissible in a civil action.

The underlying crash evidence remains important: photographs, witnesses, measurements, vehicle data, video, roadway evidence and expert reconstruction.

Loss of Control Is Not Automatic Negligence

A vehicle crossing a center line or leaving its lane is powerful evidence to investigate, but Wyoming does not presume negligence merely because a collision occurred.

In a winter-weather crash, determine whether the condition was known, reasonably foreseeable, sudden or unexpected.

temperature
snow or ice
road treatment
visibility
posted speed
actual speed
following distance
tire condition
vehicle condition
prior road conditions
warning signs
driver familiarity

Sudden Emergency

Wyoming continues to recognize sudden emergency as a circumstance relevant to determining whether a person acted reasonably.

It is not a separate license to disregard ordinary care and should be applied cautiously.

Important questions include:

Did a genuine emergency actually arise?
Was it sudden and unexpected?
Did the driver help create the emergency through prior negligence?
What alternatives were reasonably available?
Was the reaction reasonable under those circumstances?

The Crash Investigation Should Reconstruct Conduct, Not Conclusions

Preserve the scene. Photograph roadway geometry, signals, signs, marks, debris, obstructions and sight lines.

Preserve vehicle evidence. Damage patterns, event-data information, tires, lights and vehicle condition may establish speed, movement and impact.

Identify witnesses and video. Nearby vehicles, businesses, homes and traffic systems may possess evidence that disappears quickly.

Identify every causative actor. Do not limit the analysis to the two names on the police report.

Map each person's duty and conduct. Speed, lookout, yielding, lane use, control, impairment, distraction and other circumstances.

Analyze proximate causation. Separate conduct that merely existed from conduct that actually contributed to the crash or injury.

Only then allocate comparative fault. Fault percentages are conclusions reached from the reconstructed evidence.

Crash Evidence Checklist

police crash report
scene photographs
vehicle photographs
body-camera video
dash-camera video
business surveillance
residential cameras
traffic-camera material
911 recordings
witness identities
event data recorder
vehicle telematics
cellphone evidence
GPS information
weather records
road-maintenance records
skid or tire marks
debris field
sight-distance measurements
traffic-control devices
vehicle inspection
driver statements

Leading Wyoming Authorities

Bunning v. Romero, 2026 WY 40 Wyoming's current automobile comparative-fault anchor. A statutory right-of-way does not eliminate the preferred driver's duty of reasonable care.

Oberson v. Shreeve, 1983 WY 129, 672 P.2d 1294 Demonstrates comparative allocation between drivers where both contributed to the collision.

Short v. Spring Creek Ranch, 1987 WY 9, 731 P.2d 1195 Rejects an inflexible rule treating every statutory violation as negligence per se and recognizes statutory violations as evidence in the negligence inquiry.

Roberts v. Estate of Randall, 2002 WY 115, 51 P.3d 204 Confirms that sudden emergency survived comparative negligence but is a circumstance within the reasonable-care analysis and must be supported by the evidence.

Cardenas v. Fossen, 2024 WY 117 Reaffirms that a crash or loss of vehicle control does not itself create a presumption of negligence; the plaintiff retains the burden of proof.