New data indicates that almost half a million cars in the UK are not paying taxes, which has prompted worries about safety.
Department for Transport (DfT) data shows that 498,000 registered vehicles have unpaid vehicle excise duty (VED).
This is equivalent to one in every 83 vehicles.
Among the untaxed cars spotted in traffic, over a quarter (24%) have been so for longer than six months.
Nicholas Lyes, director of policy and standards at road safety charity IAM RoadSmart, said: “It will be hugely frustrating to the overwhelming majority of tax-paying drivers that almost half a million others are not paying their way.
“Perhaps even more worrying is that a quarter of those that are dodging vehicle excise duty have been doing so for more than six months.
“Untaxed vehicles are sometimes linked to much wider criminality and this has implications for safety on our roads.”
With 2.9% of all vehicles utilised on roads, Northern Ireland has the highest percentage of VED evasion.
The rate across the UK as a whole is 1.3%.
Steve Gooding, director of motoring research charity the RAC Foundation, said: “Leaving aside the loss of cash for the Chancellor, the worry for us all must be what else VED evaders are failing to do.
“If they aren’t prepared to pay the duty what are the chances they’re also uninsured and unroadworthy with no MOT?
“Some people may simply have forgotten to pay their VED for a week or two, or perhaps failed to update their records when they move house, but evasion on this scale could be a sign of more serious issues for road safety.”
Ever since the paper tax disc was eliminated in October 2014, the amount of money lost due to nonpayment of VED has increased.
Because of doubts regarding the validity of the approach, the DfT declared that it would not release a revised estimate of the amount of money lost.
The most recent annual estimate for Britain, which was released two years ago, increased the amount from £35 million in 2013–14 to £114 million.
Although notices are provided by the Driver and Vehicle Licencing Agency (DVLA), the visual in-car reminder of the VED expiration date was eliminated with the removal of the paper disc.
At the time, the Government claimed that the DVLA would eventually save almost £7 million annually as a result of the move.
A portion of the money lost due to VED evasion is recovered by the DVLA’s enforcement actions.
DVLA chief executive Julie Lennard said: “As 98.7% of vehicles on the road are taxed correctly, it is very clear that the vast majority of drivers make sure they do the right thing and ensure their vehicle is taxed.
“However, we will continue our work to keep evasion rates low by continuing to make vehicle tax easy to pay but hard to avoid.”
If a car registered in the UK is driven or parked on a public road, it has to be taxed. The quantity fluctuates according on the CO2 emissions of a car.
The standard penalty for nonpayment is £80, but if a case goes to court, the maximum punishment is £1,000.
The DfT said its evasion figures are not comparable with those from previous years because of an improvement in identifying the movement of personalised number plates between vehicles.