Average speed cameras on the A19: This is when will the cameras for the Testo's Roundabout roadworks be switched on and how they'll work

The scheme, which will take more than two years to complete and cost up to £159.4 million, will see the interchange replaced to reduce journey times and tackle congestion problems at peak times.

It will see the A19 raised on a flyover and new slip roads built to connect the A184 Newcastle Road .

This means traffic using that busy section of one of the North East’s busiest routes will no longer need to stop at traffic lights at the roundabout.

Work will also take place at the Downhill Lane, which is one of the main access routes to Nissan and the planned International Advanced Manufacturing Park (IAMP), which aims to bring thousands of new jobs to the region.

A demolition project to remove a bridge on the stretch of the carriageway is always complete.

Speed restrictions of 40mph and 50mph have been in place since the work began, with a set of average speed cameras put in place last week.

But motorists should be warned it won’t only be the average speed cameras keeping a check on people’s driving.

Inspector Dean Hood said: “Northumbria Police are committed to making our roads as safe as possible and we work closely with partners every day to enforce speed limits across our region.

“Using speed enforcement cameras is just one tactic we use to prevent dangerous driving on our roads and we will continue to do what we can to ensure motorists use our roads safely.”

Here’s what you need to know about the scheme as the work moves forward.

When will the speed cameras be switched on?

The cameras are due to be switched on at the end of July, the Highways Agency has said.

How long will the cameras be there for?

The cameras will be in place until the end of the project. The £91.1million project to improve the Testos roundabout and Downhill Lane started in March and the end date is estimated to be sometime in late 2020 or early 2021.

Will the average speed cameras be in operation 24-hours a day? Do average speed cameras work in the dark?

The cameras will be in operation 24/7. Despite the rumours that they don’t work in the dark the Highways Agency have said the cameras use infrared technology and lights so they can catch you in the dark.

How to do they work?

They use automatic number plate recognition (ANPR) to get accurate timings between cameras. The average speed of a vehicle is then calculated over the distance travelled.

Why have they only just been installed, rather than when the restrictions begun? Is it because people were ignoring the signs?

Installing the safety cameras earlier would have had caused more disruption to drivers using this route as lane closures were necessary to do so, the Highways Agency has said.

What fines and penalties will drivers face if they breach the restrictions?

If an offence of speeding is detected the matter may be resolved with a speed awareness course, fixed penalty of £100 and endorsement of three penalty points or a court hearing in some circumstances.

What happens to the money generated by the fines?

Any fines imposed from court hearings or fixed penalties go direct to central Government, they aren’t kept by the local police forces.

How many are there on each side of the A19 and how far apart are they spaced?

There are 14 safety cameras in total – six northbound, six southbound and two covering the eastern approach on the A184.

Can people still expect to see speed vans and police stop checks?

As Northumbria Police has warned, motorists can expect officers to be watching out for any offences on the road.