Commuters are being forced to take a four-mile diversion along the M11 in the latest round of A14 roadworks.

The diversion has caused confusion for some motorists who didn't realise the two week closure of the crucial Girton interchange junction had begun.

Major structural works are planned, which means motorists are being re-routed to Dry Drayton.

Why is the diversion in place?

The road has been closed while the embankments on the M11 are strengthened.

Highways England are using a colossal 39,000 kilos of a new filling material which they say should make the road safer for the 40,000 drivers a day who use it.

The 'innovative' material will be used to fill underground gaps at the Girton Interchange.

The "underground voids" were discovered during routine surveys, says Highways England.

Highways England are working to improve embankments on the M11

It's thought the damage was caused by groundwater seeping in during spells of extreme weather, especially unseasonable heavy rainfall.

Highways England warned that the works were crucial so the water damage doesn't erode more of the embankment or the M11 itself.

What is the diversion and how long will it last?

The four-mile diversion started on Monday (September 24) and is expected to last until October 8.

The northbound slip road will be closed day and night while the works are taking place.

Drivers wanting to exit the M11 at junction 14 to go eastbound will have to continue along the M11 where it merges with the A14 northbound.

At junction 30 of the A14, at Dry Drayton, they will then have to exit and then come back on themselves, going back down the A14, this time southbound, where they will then be able to continue on the A14 going eastbound or exit onto the A428 towards Madingley.

Drivers will not be able to exit the M11(Nb) at J14 and will have to merge on to the A14, exit at J30 and then come back on themselves, back down the A14.

Westbound drivers leaving at junction 14 will need to exit at junction 14 onto the A1303 towards Madingley, where they will then be able to join the A428.

Drivers heading southbound from the A14 onto the M11 will not be affected by the closure.

According to Highways England the new material is a form of chemical grouting that can be injected into the road and hardens underground, preventing the need for the M11 to be completely dug up and resurfaced.

The engineers drill three metre boreholes into the embankment horizontally and vertically before injecting the special grouting.

Drainage works will also be completed during the two week project.

Confusion for motorists

One commuter, who did not want to be named said: " I didn't even realise the A14 junction was closed. I'm not from Cambridge, I just work here so to get there and see the signs and bollards really threw me and I didn't know which roads to take. The diversion is long and takes you into some traffic so I was 30 minutes late to work. It's causing chaos. It should be done overnight. "

Why is the work being done now?

Highways England project manager Karl Brooks:

“Safety is paramount in the work we do at Highways England, so we need to complete this work as swiftly as possible.

“We need to complete this work at Girton before the colder winter months set in, as such weather could cause further deterioration, so we’re keen to remedy the voids before that happens. We ask drivers to be patient while we’re working as we appreciate this work is likely to cause some disruption in a busy area, though the work we are doing is essential maintenance to ensure safety, so please plan your journeys and drive appropriately through our roadworks.”