Foreign drivers who break UK traffic laws can now be issued with an instantly payable fixed penalty fine.
Until now, police could arrest foreign drivers for only serious offences, such as drink-driving, which allowed many to escape paying fines after they left the country.
Foreign drivers can now face 60 fixed penalty fines for offences such as using a mobile phone while driving or speeding. The driver's vehicle can also be immobilised until payment is made.
Around three million foreign-registered vehicles come to the UK each year and around one accident in 50 involves a foreign vehicle.
Police can now issue fixed penalty fines for speeding, driving longer hours than permitted, or having a dangerous vehicle.
More serious offences, such as tailgating, will attract an immediate fine of 300. Foreign drivers who commit more than one offence could be forced to pay up to 900.
The new penalty notices are aimed at cutting the number of drivers who escape paying fines because their foreign-registered vehicles cannot be traced.
In January, the Metropolitan Police revealed that its speed cameras were activated at least once every hour by foreign-registered vehicles in 2007-8.