The prediction follows analysis of the number of fines National has received for its vehicles across the whole of the UK in the past year.
PCNs comprise parking fines, congestion charge fines, bus lane and speeding fines. In the first four months of 2004, National received a total of 19,100 PCNs for customers driving the company's rental vehicles.
Yet in 2003, the total number of fines received for the entire year was only 54,000. These comprised 15,000 parking fines, 15,000 fines for speeding offences, 22,000 congestion charge fines and 2,000 bus lane fines.
Brian Jayes, vice-president UK operations said: 'Fines are increasing across all areas of the UK, not just London where the congestion charge was introduced in February 2003.
'Many cities are increasing parking restrictions, speed cameras and 'yellow box' offences. Cardiff is the most recent city to introduce bus lane fines, some boroughs of London are just implementing trials of 'yellow box' cameras to catch culprits and other cities are following with similar initiatives during the year.
'Added to this, with Ken Livingstone's re-election as Mayor of London, it looks fairly likely that the London Congestion Zone will expand, plus Edinburgh and other cities seem set to introduce their own congestion charge zones.'
National has a team dedicated to dealing with PCNs incurred by its customers and, like other rental companies, due to the time and resources spent handling these fines, it charges an administration fee to cover its costs.
Jayes said: 'The clear message is that drivers need to be much more careful. With the vast majority of these fines costing upwards of £10 – and many in the £40 region – they will be hitting the pockets of both businesses and consumers. While some drivers may regard PCNs as a fact of life, the growing number of businesses which end up paying these charges should consider the long-term impact of drivers not sticking to the law, or paying congestion charges on time.'