A North Wales driving instructor said the new blanket 20mph is causing  "confusion, chaos and mayhem".

Stuart Walker, a driving instructor and consultant with SWT Driver and Training Consultancy, has 35 years of experience in the sector.

Reporter Joe Robinson went on a drive with him around Wrexham to see first-hand some of the issues motorists are facing because of the new 20mph limit.

"I'm all for 20mph on roads which are suited to it," he said.

"But the scope of the new speed limit is such that there are many roads where it's frankly ridiculous to be driving at 20mph."

Earlier this week, a report was released by public health data analyst Agilysis.

The company studied several stretches of road in North Wales, including Rhyl and Prestatyn, Bangor, and Wrexham, using GPS technology.

Agilysis said the results were "astonishing".

In Wrexham, they found that the median average speed of the vehicles studied was 19.6mph, and by over 3mph across all the roads studied in the county borough. Sample analysis of the A5152 Chester Road showed that journey times increased by 45-63 seconds along the two 2.5km route.

However, Mr Walker said the study can be "ripped to pieces".

"Even if traffic speed has reduced by 3mph its probably because traffic gets behind a learner driver or police car doing exactly 20mph," he said.

"Average speed will drop because of the grid lock bunching has caused. The 20mph speed limit has also brought out all the Sunday drivers. They are driving at under 20mph and causing havoc everywhere they go."

He added: "They claim the average speed on Chester Road in Wrexham is now 19mph - that is due to gridlock. Last Monday morning I was on a lesson and everyone on Chester Road towards Wrexham was held up and most turned around to go back to Gresford roundabout. 

"If the authorities are using data from tracked vehicles perhaps they could tell us what the highest speed recorded in a 20mph was. What average speed were all the untracked vehicles doing? Tracked vehicles are normally work vehicles so good behaviour is the norm."

The new speed limit has also affected his business as a driving instructor. 

"Journeys are taking longer, so I'm getting less clients," he said. "This means I have to increase my prices, which is a direct effect on the economy by 20mph."

Mr Walker, an award-winning lorry driving instructor, believes the 20mph limit has made drivers "angry" which he believes "will not improve road safety".

"We have already had one near-miss in a lorry as a car overtaking others on a bend just missed us," he added. 

On the journey, Mr Walker showed us some of the erroneous signage which remains in place following the introduction of the new speed limit on September 17. 

On the A5152 near Tesco, there are signs telling drivers they are in a 30mph zone - despite it being a 20. 

"I know the Welsh Government has told people to ignore the signs," Mr Walker said. "But these signs make it seem very much like it's a 30 zone. It's not just confusing for learners, but for all motorists."

Another area with confusing signage is Llay New Road, near the cemetery. A section of that road remains 30mph, but only in one direction is there signage telling drivers so. 

Mr Walker said: "It means that in the other direction, people are still doing 20mph - as there are no signs telling them they've entered a 30 zone. It's ridiculous.

"It's bound to cause confusion, chaos and mayhem."

One of the key drivers of the Welsh Government policy is helping reduce the number of people requiring hospital treatment following road traffic collisions. Stuart acknowledges 'impact speeds are important' but added, 'a new road safety initiative must be done sensibly.'