Motorists with a clean record of 10 years or more can get off most parking, speeding and even negligent driving fines just by writing a letter, it can be revealed. And a rail commuter issued with a $100 fare evasion fine can get a waiver with proof of past ticket purchases and no fare evasion history for five years.

The State Debt Recovery Office has gone public for the first time with its complete "mercy book" - its official guidelines on when it may be lenient with fines and what documentary evidence is needed. The 42-page SDRO Review Guidelines was quietly put on its website last month.

Its release comes as record numbers of fines are being issued, including a doubling in 2007 of the value of fines issued by fixed speed camera fines to $71.6 million. Based on the exemptions outline in the guidelines, it is likely that thousands of motorists pay fines they could avoid.

The 10-year clear driving provision applies to a wide range of traffic offences but not all. It applies to parking, speeding, traffic light, seat belt, T-way, bus lane and negligent driving offences.

However, the exemption does not apply to the tens of thousands of motorists caught speeding in school zones. It also does not apply to mobile phone use while driving, invalid use of disabled parking permits or exceeding the speed limit by more than 30km/h.

Exemptions apply to most fines, including if the fine was issued to the wrong car, and if the vehicle was stolen or had been sold but can only be made if proof can be provided. Camera-detected offences can be also be transferred from the vehicle's registered owner to another person if that person was driving at the time.

A driver can claim a waiver if they left their vehicle to get change for a parking meter, the meter was faulty or was unfamiliar with the ticket machine. The fine can be waived too if you can prove you suffered from a medical condition that made stopping or parking the vehicle necessary or it was a medical emergency.

Similarly, visiting someone in a hospital "and their condition worsened and death was imminent and it was not reasonable to leave at that time", is reasonable grounds for an exemption. A letter on official letterhead from a medical professional would be required.

Rail fare evaders can also get off their fine if they can show they were a first-time user of the rail system, there were not ticket selling facilities, or the offence was committed "as a result of service disruptions". A spokeswoman for the SDRO said information on its review guidelines had been going up on the website since last year.

"The SDRO acknowledges there are times where extenuating circumstances may not necessarily be known to the issuing officer when the fine is issued," she said. She cautioned that the guidelines were "not meant to be a list of excuses to get out of a fine."