The Ontario Fault Determination Rules (commonly known as the Fault Rules or FDR) is a regulation under the Ontario Insurance Act enacted by the Parliament of Ontario to judge driver responsibility after car accidents in Ontario. The Fault Rules say which driver was responsible for an accident. Accidents are either 0%, 25%, 50%, 75%, or 100% at fault. If the driver is from Ontario, the portion not at fault percentage is covered under Ontario's mandatory to buy Direct Compensation insurance, and the at fault portion is covered under the optional to buy Collision insurance.

A fault rating between 50–100% might affect the driver's and insurance policyholder's future risk factor and therefore future insurance rates. Note auto claim's using Specified Perils/Comprehensive for events like theft, vandalism, or hail damage are not subject to a fault rule (but may affect insurance rates and coverage depending on policyholder's claim history).

The Fault Rules are for most every accident in Ontario. However, under some rare conditions the Fault Rules do not apply and accident responsibility is determined by car accident case law. Car accidents outside of Ontario are governed by the Provincial or State where it happened. Each respective regulation is similar to these Fault Rules, but differences do exist, see the correct jurisdiction's fault rules for their details.

Basic Rules

The Fault Rules have several basic conditions. These conditions specify that insurance companies have to use them when determining fault, and that circumstances like weather or road conditions do not matter when determining which driver was responsible.

The conditions are:

Rule Section Insurance companies determine fault, through direct or indirection action of its insured persons, using the fault rules. 2.1FDR S. 2.1 "An insurer shall determine the degree of fault of its insured for loss or damage arising directly or indirectly from the use or operation of an automobile in accordance with these rules.". Fault is determined without caring about the circumstances, including the weather conditions, the road conditions, visibility, or actions of pedestrians. 3.aFDR S. 3.a "The degree of fault of an insured is determined without reference to, (a) the circumstances in which the incident occurs, including weather conditions, road conditions, visibility or the actions of pedestrians.". Location of the damage on a car, isn't evidence of what happened at the accident. 3.bFDR S. 3.b "The degree of fault of an insured is determined without reference to, (b) the location on the insured’s automobile of the point of contact with any other automobile involved in the incident.".

Evidence

Determining car accident fault requires knowing what happened at the accident. Re-creating an accident can be difficult. To deal with this most fault rules have a version for knowing the details of the accident, and not knowing (ex. accidents in the middle of an all-way stop).

The following are the ways accident details are collected.

Driver accounts to either an insurance adjuster or police officer. Independent witnesses. On site police reports (if the police say for sure what happened). Dashboard camera video.

How much at fault

A car accident can have one or several Fault Rules that apply. If an accident has only one Fault Rule, then the one rule's rating puts each driver 0–100% at fault.

If there are several rules that apply then the rules below apply too.

{| class="wikitable" ! style="text-align: center; | Rule ! style="text-align: center; | Section |- | style="text-align: center;" | If multiple rules apply to an insured person, then the one that gives the least fault is used. | style="text-align: center;" | 4.1FDR S.4 (1) "If more than one rule applies with respect to the insured, the rule that attributes the least degree of fault to the insured shall be deemed to be the only rule that applies in the circumstances.". |- | style="text-align: center;" | However, despite 4.1, if each insured driver breaks a fault rule so each driver is both 0% at fault, and 100% at fault, then each driver is 50% at fault | style="text-align: center;" | 4.2FDR S.4 (2) "Despite subsection (1), if two rules apply with respect to an incident involving two automobiles and if under one rule the insured is 100 per cent at fault and under the other the insured is not at fault for the incident, the insured shall be deemed to be 50 per cent at fault for the incident.".

What if no Fault Rule applies

There are some rare accidents when no fault rule can apply.

If that happens then these rules apply:

{| class="wikitable" ! style="text-align: center; | Rule ! style="text-align: center; | Section |- | style="text-align: center;" | If an incident is not described in any of the Fault Rules, then an insured driver is judged according to the ordinary rules of the road (case law). | style="text-align: center;" | 5.1FDR S. 5 (1) "If an incident is not described in any of these rules, the degree of fault of the insured shall be determined in accordance with the ordinary rules of law.". |- | style="text-align: center;" | If there isn't enough information to know what happened, then the insured driver is judged according to the case law. | style="text-align: center;" | 5.2FDR S. 5 (2) "If there is insufficient information concerning an incident to determine the degree of fault of the insured, it shall be determined in accordance with the ordinary rules of law unless otherwise required by these rules.".

The Fault Rules

The below sections are the actual Fault Rules. Each is divided into sections describing where the two (or more) cars are relative to each other.

Rear End

Rule"A""B" Section Section 6.x applies when automobile "A" is struck from the rear by "B" and both vehicle's are in the same lane, going in the same direction. n/a n/a 6.1FDR. S. 6.1 "This section applies when automobile “A” is struck from the rear by automobile “B”, and both automobiles are travelling in the same direction and in the same lane.".

Rule 6.2

{| class="wikitable" ! style="text-align: center; | Rule ! style="text-align: center; |"A" ! style="text-align: center; |"B" ! style="text-align: center; | Section |- | style="text-align: center;" | If driver "A" is stopped or in forward motion, and is rear ended by driver "B". | 0% | 100% | style="text-align: center;" | 6.2FDR. S. 6.2 "If automobile “A” is stopped or is in forward motion, the driver of automobile “A” is not at fault and the driver of automobile “B” is 100 per cent at fault for the incident.".

Rule 6.3

{| class="wikitable" ! style="text-align: center; | Rule ! style="text-align: center; |"A" ! style="text-align: center; |"B" ! style="text-align: center; | Section |- | style="text-align: center;" | If "A" is turning, either right or left, to enter a private road or driveway. | 0% | 100% | style="text-align: center;" | 6.3FDR. S. 6.3 "B hit A in rear – Insd turning right or left to road or drive, the driver of automobile “A” is not at fault and the driver of automobile “B” is 100 per cent at fault for the incident.".

Rule 6.4

{| class="wikitable" ! style="text-align: center; | Rule ! style="text-align: center; |"A" ! style="text-align: center; |"B" ! style="text-align: center; | Section |- | style="text-align: center;" | If "A" is going forward, and entering a road side parking place. | 0% | 100% | style="text-align: center;" | 6.4FDR. S. 6.4 "If automobile “A” is in forward motion and is entering a parking place on either the right or the left side of the road, the driver of automobile “A” is not at fault and the driver of automobile “B” is 100 per cent at fault for the incident.".

Entering a roadway

Rule"A""B" Section Section 7 applies when "B" is entering a road from a parking place, private road, or driveway. n/a n/a 7.1FDR. S. 7 (1). "This section applies when automobile “A” collides with automobile “B” while automobile “B” is entering a road from a parking place, private road or driveway.".

Rule 7.2

{| class="wikitable" ! style="text-align: center; | Rule ! style="text-align: center; |"A" ! style="text-align: center; |"B" ! style="text-align: center; | Section |- | style="text-align: center;" | If accident happens when "B" is leaving a parking place while "A" is passing it. | 0% | 100% | style="text-align: center;" | 7.2FDR. S. 7 (2). "This section applies when automobile “A” collides with automobile “B”, and both automobiles are travelling in the same direction and in adjacent lanes.".

Rule 7.3

{| class="wikitable" ! style="text-align: center; | Rule ! style="text-align: center; |"A" ! style="text-align: center; |"B" ! style="text-align: center; | Section |- | style="text-align: center;" | If accident happens when "B" entering the roadway from a private road or driveway "A" is passing it, and there are no traffic controls. | 0% | 100% | style="text-align: center;" | 7.3FDR. S. 7 (3). "If the incident occurs when automobile “B” is entering a road from a private road or a driveway and automobile “A” is passing the private road or driveway and, if there are no traffic signals or signs, the driver of automobile “A” is not at fault and the driver of automobile “B” is 100 per cent at fault for the incident.".

Entering from On Ramp

Rule 8

{| class="wikitable" ! style="text-align: center; | Rule ! style="text-align: center; |"A" ! style="text-align: center; |"B" ! style="text-align: center; | Section |- | style="text-align: center;" | If accident happens when "B" entering the roadway from an on-ramp. | 0% | 100% | style="text-align: center;" | 8.0FDR. S. 8. "If automobile “A” collides with automobile “B” on a controlled access road while automobile “B” is entering the road from an entrance lane, the driver of automobile “A” is not at fault and the driver of automobile “B” is 100 per cent at fault for the incident.".

Multi Car Rear End - Chain Reaction

Rule"A""B""C" Section Section 9.x applies when more than two cars are in a rear end accident. 100 n/a n/a 9.1FDR. S. 9 (1). "This section applies with respect to an incident involving three or more automobiles that are travelling in the same direction and in the same lane (a “chain reaction”).". Fault is only between cars that touch. 0 n/a n/a 9.2FDR. S. 9 (2). "The degree of fault for each collision between two automobiles involved in the chain reaction is determined without reference to any related collisions involving either of the automobiles and another automobile.".

Rule 9.3 a-b

{| class="wikitable" ! style="text-align: center; | Rule ! style="text-align: center; |"A" ! style="text-align: center; |"B" ! style="text-align: center; |"C" ! style="text-align: center; | Section |- | style="text-align: center;" | If all vehicles are in motion, and "A" is lead, "B" is middle and "C" is last. | style="text-align: center;" | n/a | style="text-align: center;" | n/a | style="text-align: center;" | n/a | style="text-align: center;" | 9.3FDR S. 9 (3). "If all automobiles involved in the incident are in motion and automobile “A” is the leading vehicle, automobile “B” is second and automobile “C” is the third vehicle.". |- | style="text-align: center;" | In collision between "A" and "B". | style="text-align: center;" | 0% | style="text-align: center;" | 50% | style="text-align: center;" | n/a | style="text-align: center;" | 9.3.aFDR S. 9 (3)(a). "In the collision between automobiles “A” and “B”, the driver of automobile “A” is not at fault and the driver of automobile “B” is 50 per cent at fault for the incident.". |- | style="text-align: center;" | In collision between "B" and "C". | n/a | 0% | 100% | style="text-align: center;" | 9.3.bFDR S. 9 (3)(b). "In the collision between automobiles “B” and “C”, the driver of automobile “B” is not at fault and the driver of automobile “C” is 100 per cent at fault for the incident.".

Rule 9.4 a-b

{| class="wikitable" ! style="text-align: center; | Rule ! style="text-align: center; |"A"