Research from the RAC Foundation has shown that, while the congestion charge has slashed the number of cars entering the city by a staggering 50,000 a day, the number of appeals against incorrect penalties is set to hit 35,000 compared to the 7,000 predicted by Transport for London (TfL).
Edmund King, executive director of the RAC Foundation, said: 'The London scheme is working well in terms of traffic reduction in the centre without causing too many problems outside the zone.
'After 12 months, the mayor should be congratulated on the fact that the scheme has exceeded expectations on traffic reduction.
'But more needs to be done to measure the adverse effects on the economy of London and to improve administration so that innocent motorists are not penalised.'
The economic viability of the scheme remains in the balance as TfL expected to generate £108 million from charges but has reduced its forecast to £68.4 million.
The congestion charge has also had a detrimental effect on businesses in the charging zone. Many have noted a slump in business as motorists have been deterred from entering by the £5 levy.
Vehicle management provider Fleetline completed research on the congestion charge, finding that 82% of small to medium-sized enterprises (SMEs) saw no benefit to businesses within the zone.
Fleetline director David Harnett said: 'With the majority of SMEs not perceiving any clear business benefits from the congestion charge and only 25% seeing road tolls as a solution to Britain's overcrowded roads, these statistics demonstrate that small and medium-sized businesses are not fully supportive of road charging.
'We have also found that there has been confusion over who is responsible for payment of the charge, leading to fines and associated administration costs. Companies need to make it clear where the responsibility lies by clearly communicating policy to employees.'
However, an independent survey produced by business organisation London First suggests almost three-quarters of London's businesses believe the congestion charge is working.
The survey found that 65% believe there has been no real impact on their bottom line and 50% have not seen costs increased or changed. Nearly half though would like to see an easier system for registering and paying.
Before the scheme is introduced on a national scale, problems such as incorrect fines and the effects businesses within the city need to be ironed out, according to King. He said: 'Central London is unique as 86% of commuters used public transport before congestion charging was introduced in London.
'In every other city, the majority commute by car and most UK cities rely on the bus as the main means of public transport.
'In order for these cities to introduce a successful scheme, they will have to invest heavily in public transport and park and ride up front.'