Drivers across the UK have been plagued by traffic jams and tailgating as people head home after the four-day Easter weekend.

Congestion is expected to be worst in south-west England as an estimated two million holidaymakers return today.

It comes after the RAC warned of a possible “carmageddon” ahead of the Easter holidays, saying it expected traffic jams and long queues.

Tailgating was seen on the M5 motorway between Bristol and Taunton, as well as at the A102M Blackwall Tunnel in Greenwich, south-east London.

Traffic was backed up on some sections of the M5, with speeds reaching 16mph, and delays of up to 30 minutes in many home counties.

A major traffic accident also occurred this afternoon between junctions 23 and 24 of the M60 just outside Denton, Greater Manchester.

The “serious” incident forced the motorway to be closed in both directions and an air ambulance was spotted at the scene.

Queues stretched for 15 to 20 miles on the M4 and M5 interchanges near Bristol on Good Friday, adding 45 minutes to journey times.

The west side of the M25 London Orbit motorway was described as “very bad” and “much worse than normal”, with queues lasting up to 40 minutes.

The RAC said holidaymakers heading south were the main cause of the congestion after forecasters predicted sunny weather over the coming days.

Simon Williams, a spokesman for the RAC, said: “Everyone is heading to Devon and Cornwall – that’s the attraction, and the weather is better. That leads to some pretty horrendous queues.”

The M20 in Kent is also busy, with congestion approaching Folkestone on the coast. The A628 between Greater Manchester and South Yorkshire is also experiencing delays after two separate incidents, the National Highways Agency reported.

Around 11 million people in the UK are planning Easter overnight trips, which are expected to bring £3.2 billion to the UK economy, tourism board VisitEngland said.

A survey by the RAC and transport analytics company Inrix shows that around 14 million road journeys are expected to take place over the weekend.