Over 125,000 people are expected to go to the concerts

The pop star is appearing at Knebworth from Friday 1 August until Sunday 3 August.

Over 125,000 people are expected to make their way to the venue over the three days, with an extra 30,000 cars and 400 coaches travelling in the area every day.

Over 20,000 people are expected to arrive at the venue by train.

Andy Shilliday, Highways Agency assistant route manager said: "We are putting emergency traffic arrangements in place on the A1(M) trunk road to ease access at Junction 7 for Knebworth House.

"However, major motorways and trunk roads leading to the event are likely to be busy before and after the concerts.

"The Highways Agency is advising drivers to plan their journeys in advance and to avoid trouble spots if they can."

Junction 7 on the A1(M) will be closed to non-event traffic from 1730 BST on the Friday until 0600 BST on Monday 4 August.

Diversions will be put in place.