Viv Williams was so angry at his fine he arranged the protest meeting

They said many of the drivers caught on a speed camera near the Maesgeirchen estate were within the old 40mph limit before it was reduced to 30mph.

The protest group, of about 100 people, says it is seeking legal advice.

Gwynedd Council, as part of the Arrive Alive partnership, said it followed legal guidelines in publicising change.

The switch took place in July and was followed by the placing of the Arrive Alive mobile speed camera in the area soon afterwards.

Arrive Alive is run by North Wales Police, local authorities and a number of other organisations, and uses marked vans to capture speeding motorists.

"What we've discovered is that many people who have been fined were within the old restriction of 40mph," said meeting organiser Viv Williams, who said he was caught doing 38mph.

Busy junction

"On the day I was caught I saw the Arrive Alive speed camera van and I checked to make sure I was within the 40mph because I didn't know it had been reduced.

"The change in the speed limit happened virtually overnight and many people didn't know about it."

Gwynedd Council said: "The speed restrictions were introduced as part of a transportation project to improve road safety for all road users on what is a very busy junction.

"Prior to introducing the speed restrictions, Gwynedd Council placed a notice in the local press and on the site in accordance with legal procedures."

Following the protest meeting a small group of motorists are set to meet to write a letter complaining about their treatment, and there are also moves to seek legal advice.