The cause of long tailbacks on the A2 stretching from Brenley Corner to Canterbury is under investigation by Highways England.

Many drivers have spent over an hour edging towards the roundabout in rush hour traffic this week.

But although Highways England is aware of the situation, engineers remain unsure as to why queues have not subsided.

Crashes contributed to delays on Tuesday when the driver of a Ford Fiesta suffered chest, leg and facial injuries after his car collided with two lorries on the A2 at Harbledown.

The A2 was closed in both directions while emergency services dealt with the incident and for the Kent Air Ambulance to land.

The next day there were queues between Canterbury and Brenley Corner following another crash involving a lorry and a car.

The London-bound carriageway was partially blocked and traffic backed up several miles towards Canterbury.

But the reason for continuing queues have been unclear and despite rumours of a traffic light fault at the roundabout, Highways England is unable to confirm the problem at this stage.

Highways England spokesman Andrew Broughton said: "We are not entirely sure at the moment, engineers are establishing whether there is a mechanical fault with the traffic lights at the roundabout or whether traffic flows have changed as a result of other nearby road closures.

"There is no realistic timescale of fixing the problem, it is something our engineers will be monitoring.

"For the time being we advise drivers to plan their journeys accordingly."