Why M6 driver flashed by camera despite driving at 70mph

The driver reported being flashed near junction 25 while driving at the legal 70mph limit and questioned whether there was a fault with the camera, signage or a temporary variable speed limit they might have missed.

National Highways said the cameras occasionally flash randomly and can be triggered even if a vehicle is not speeding.

Hi, ive just been driving down the M6 and got flashed for doing 70 but no speed sign on the signs, is there a fault with the cameras/signs today?@HighwaysNWEST

— GradientWizzard (@GradientWizzard) September 14, 2026

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National Highways said: “We maintain the cameras but their data and readings go to the local police for them to enforce.

“The cameras are designed to recalibrate themselves on occasion, causing them to flash, so they’re always operationally ready should they need to activate.

“This means they can be triggered even if the vehicle is not speeding.”

What are variable speed limits?

According to National Highways, variable speed limits (VSL) are displayed on illuminated signs on the side of the motorway or on gantries above the lanes.

A speed limit displayed within a red circle is legally enforceable, regardless of the reason for its implementation.

When a VSL changes, the associated speed camera performs a self-check, which can cause a flash even if the vehicle is not exceeding the limit.

National Highways said: “This flash does not necessarily indicate that your vehicle has been identified as exceeding the displayed speed limit.

“To allow drivers to reduce their speed safely, the police ensure a minimum time delay between any change to the variable speed limit displayed and the enforcement of that new speed.”

Enforcement of variable speed limits is a police responsibility.

National Highways provides the speed detection equipment, but all evidence is collected and held by the police.

A spokesperson for National Highways said: “We’re not a law enforcement authority and are not responsible for the enforcement of the variable speed limits which we set.

“The police are responsible for all matters concerning the enforcement of VSLs.

“All evidence required for the prosecution of speed offences on our motorways is collected by the police.

“We don’t collect or hold such evidence.”

The cameras are equipped with video systems that record the displayed speed limit at the time of the alleged offence, ensuring that the limit is visible and enforceable.

National Highways said: “This provides assurance that the limit being enforced is visible to drivers.

“If the camera can see and interpret the speed limit, then we know that drivers can see and interpret the same signs.”