More than 700 foreign drivers escaped speeding fines on Yorkshire roads last year because their cars cannot be easily traced.
Humberside Police recorded 584 speeding offences, with one driver notching up 90mph on the M180 in North Lincolnshire, which were not pursued, according to road safety charity the Institute of Advanced Motorists.
South Yorkshire tracked down some offenders, but let go 120 who were not registered with the DVLA.
The two other regional police forces did not reply to their Freedom of Information request, suggesting the true extent of the problem is far higher.
Overall more than 23,000 drivers – including one who clocked up 111mph on the M25 – escaped action.
The figures come as a report by Safer Roads Humber revealed 46,360 drivers were caught speeding last year. Over half went on courses, with most of the rest being fined just over £1m. Numbers were up around 12 per cent last year, with 6,000 alone caught speeding in just three months on Peaks Parkway, Grimsby.
Neil Greig, from the IAM, said: “There’s a DVLA in very country but they just don’t talk to each other. The high numbers of oversees speeders show how important it is that the UK joins up with the rest of Europe to harmonise motoring offences and give the police extra powers to pursue dangerous drivers.
“Progress on this issue has been very slow and in the meantime thousands of drivers are avoiding fines and bans.”
Earlier this year the RAC urged the Government to take action on the number of untaxed foreign cars. Around 15,000 are not registered, avoiding around £3m in tax.