A driver has been caught doing 145mph on a dual carriageway in Devon, the fastest speed ever recorded by Devon and Cornwall Police.
Road users are being told speeding is not worth the risk
The vehicle was clocked on the A380 near Torbay by a mobile camera.
The Devon and Cornwall Safety Camera Partnership, which owns the mobile camera, said such a speed showed a disregard for other people's safety.
Police are considering prosecuting the driver not for speeding but for the greater offence of dangerous driving.
Dangerous driving is an offence which carries a possible prison sentence of up to two years.
Aurea Billings, from St Austell, Cornwall, knows personally the lethal effect of speeding.
Her son, Sam, was killed by a driver doing 60mph in a 30mph limit.
She said: "It's your worst nightmare when you get that knock on the door.
"You think your world comes to an end, and the feeling never goes away because it comes to you every day."
On hearing what speed the driver in Torbay was doing, she said: "Nothing is worth the risk of killing somebody at great speed."
The Devon and Cornwall Safety Camera Partnership said no more details could be given about the motorist because a police investigation was under way.
The Partnership said its monitoring systems revealed that speeds generally were coming down.
"However, there is still a small minority of motorists who feel that the law does not apply to them and that they are entitled to drive with total disregard
for the safety of others," said a spokesman.
In 2003, 76 people were killed on Devon and Cornwall's roads.