Many motorists are familiar with traditional speed cameras, but average speed cameras work differently. Rather than measuring your speed at a single point, they calculate your average speed over a set distance.
These systems are now widely used across England on motorways, major roads and roadworks, and they have become an effective way of encouraging drivers to maintain a consistent speed.
If you’ve received a Notice of Intended Prosecution following an alleged offence detected by average speed cameras, understanding how the technology works can help you appreciate the evidence involved and the steps you should take next.
Average speed cameras explained
Average speed cameras use cameras positioned at different points along a stretch of road. As your vehicle passes each camera, its registration number is recorded along with the time.
The system then calculates your average speed between the two points by comparing the distance travelled with the time taken.
Unlike traditional cameras, which record a vehicle’s speed at one location, average speed cameras monitor your driving over a longer distance.
Average speed is calculated using a simple formula: Average speed = Distance travelled ÷ Time taken
This means slowing down just before a camera and then speeding up afterwards is unlikely to prevent an offence being detected if your average speed remains above the legal limit.
Where are average speed cameras commonly used?
Average speed cameras are frequently installed:
- On motorway roadworks
- On smart motorways
- On major A roads
- In areas with a history of serious collisions
- Where lower speed limits are needed for road worker or public safety
Many systems operate continuously, while others may only be active during particular periods.
What happens if you’re detected speeding?
If the system records an average speed above the applicable limit, the registered keeper of the vehicle may receive a Notice of Intended Prosecution (NIP) together with a Section 172 notice, requiring them to identify the driver.
It is important to respond within the specified deadline. Failing to identify the driver can result in a separate offence, which often carries six penalty points and a financial penalty.
Depending on the circumstances, the original speeding allegation may result in:
- A fixed penalty
- A speed awareness course (where eligible)
- Penalty points
- A court hearing for more serious cases
The outcome will depend on factors such as the alleged speed, the applicable limit and the driver’s previous record.
Can average speed camera evidence be challenged?
Receiving a Notice of Intended Prosecution does not automatically mean a conviction will follow.
As with any criminal prosecution, the evidence must satisfy the legal requirements. Depending on the circumstances, issues relating to the identification of the driver, the prosecution’s evidence or the legal process may need careful consideration.
Every case turns on its own facts, and specialist legal advice can help determine whether there are grounds to challenge the allegation or whether another approach is appropriate.
Don’t ignore the paperwork
If you receive correspondence relating to an alleged speeding offence detected by average speed cameras, it is important to deal with it promptly.
A specialist speeding offence solicitor can explain your legal obligations, review the evidence and advise you on the most appropriate course of action.