How congestion fines are calculated
On 20 August 2026, fines for incidents that cause measurable traffic congestion start being calculated from the delay those incidents actually cause. The amount is no longer taken from a fixed schedule of penalties. It comes from how many vehicles were caught up in the delay and how long each of them sat in it.
The regulation belongs to the Traffic Operations Centre, and was written by Michael Delpach, Project/Contract Manager.
The formula
Fine = SF × N × D × R
| Variable | What it means |
|---|---|
| SF | Severity factor, a multiplier set by the nature of the incident |
| N | Number of vehicles affected, counted from ITS data |
| D | Average delay in minutes per affected vehicle |
| R | The rate, $0.50 per vehicle minute of delay |
It applies to all incidents where a driver's actions lead to measurable traffic delays, as determined by Intelligent Transport Systems (ITS) technology. Running out of fuel counts, as does a rear-end collision caused by distracted driving, along with anything else that disrupts normal traffic flow.
The numbers come from the ITS record. N is the vehicle count for the affected section. D is worked out by comparing the current site speed against the average site speed for that location, which gives the average delay each affected vehicle experienced. Multiply D by N and you have the total delay across all affected vehicles.
R is set by policy and currently stands at $0.50 per vehicle minute. It is reviewed annually, and any change takes effect from the date the Traffic Operations Centre publishes.
The severity factor is the only part of the calculation that is not a measurement. It is assigned according to the nature of the incident.
What the severity factor does
| Incident type | SF | Why |
|---|---|---|
| Serious multi-vehicle collision from reckless driving | 2.0 or higher | Large scale disruption and considerable risk to public safety |
| Rear-end collision from distracted driving, using a mobile phone for example | 1.5 | A serious offence that causes significant delays and poses substantial safety risks |
| Vehicle breakdown or running out of fuel, without contributory negligence | 1.0 | Delays, but generally not primarily caused by dangerous driving behaviour |
| Minor fender-bender with minimal disruption to traffic flow | 0.8 | Only slight disruption, so a reduced impact on traffic |
| Incident caused by a driver experiencing a health emergency, fainting for example | 0 | No fine is imposed, whatever delay followed |
A worked example
A driver strikes the rear of another vehicle while using a mobile phone. The crash blocks one lane of a freeway during the afternoon peak. The ITS record shows:
| Variable | Value | Source |
|---|---|---|
| Severity factor (SF) | 1.5 | Distracted driving |
| Vehicles affected (N) | 240 | ITS vehicle count for the affected section |
| Average delay per vehicle (D) | 4 minutes | Site speed compared with the average site speed |
| Rate (R) | $0.50 per vehicle minute | The prescribed rate |
Fine = 1.5 × 240 × 4 × $0.50 = $720.00
The fine payable is $720.00. Fines are rounded to the nearest dollar.
The same collision, caused instead by a driver suffering a verified health emergency, produces nothing. The severity factor is set to 0, so the calculation becomes 0 × 240 × 4 × $0.50 = $0.00 and no fine is imposed.
If the number looks wrong
A person issued a fine can ask for a review, in writing, to the Traffic Operations Centre, within 28 days of the date the infringement notice was issued.
Grounds include:
- the severity factor applied does not match the nature of the incident
- the number of vehicles affected or the delay recorded by ITS is inaccurate, or was influenced by an unrelated event
- special circumstances apply, such as a verified health emergency, mechanical failure that could not reasonably have been foreseen, or compliance with a direction from a police officer or emergency service
- the driver was not responsible for the incident
- exceptional hardship or other mitigating circumstances warrant reduction or waiver of the fine
What happens after that:
- recovery action on the fine is suspended while the review is under way
- a delegated officer who was not involved in issuing the fine reviews the ITS data, the assigned severity factor and the evidence provided
- a written decision is issued within 28 days of receipt of the request, setting out the reasons for the decision
The outcome may be that the fine is confirmed, recalculated using corrected data or a revised severity factor, reduced on the grounds of mitigating circumstances, or withdrawn in full. A person who is not satisfied with the decision may refer the matter to the relevant court or tribunal.
What gets reviewed
The regulation is reviewed periodically, so it can be amended as traffic patterns change, as technology advances, or as policy priorities shift. The current version, 1.0, is set for review on 20 August 2027.