An RAC poll of 1,727 drivers found that 61 per cent think motorway traffic has got worse over the past 12 months.
The reasons given for increased congestion include major roadworks (47 per cent) and middle-lane hogging (45 per cent).
Amanda Stretton, motoring editor at Confused.com, said: "It's unsurprising that many drivers are blaming middle-lane hogging as one of the main causes of extended motorway journey times.
"Our research showed that one in three drivers (32 per cent) admit to being a middle-lane hogger - so there's a fair few offenders out there.
"Worryingly, almost two in five (37 per cent) UK drivers are unaware that middle-lane hogging is a punishable offence and drivers can lose three points off their licence.
"This was made clear when I went out on the road to see how the offence is policed.
"It was astounding to see just how many hoggers there really are, clogging up the motorway when the left-hand lane was entirely clear.
"Middle lanes aren't for coasting in and drivers who do this can cause congestion and make other perform dangerous manoeuvres to get around them.
"Not only could you find yourself with a £100 fine or points, you could also put your own life and others at risk."
Motorists' perceptions of congestion are backed up by Department for Transport (DFT) statistics showing that 323.7 billion miles were driven on Britain's roads in 2016, up 2.2 per cent on the previous year.
A DFT spokesman said: "This Government is investing a record £23billion in our roads to improve journeys for motorists - the biggest investment in a generation.
"We are also giving councils record amounts of capital funding - more than £7.1bn up to 2021."