When a defendant is convicted of drink driving the court is required by law to disqualify him from driving for a minimum of 12-months. There is no discretion, the driving ban must be imposed.
Special reasons arguments are a legal device that turns the obligatory driving ban into a discretionary driving ban. In other words, if the special reasons argument is successful the court can decide whether or not to impose a driving ban. If courts find special reasons exist then more often than not they will not ban the defendant from driving.
A common special reason is "emergency", this is intended for situations where life or limb is at risk. The typical situation might be a specialist doctor or surgeon rushing to perform a life-saving treatment that nobody else can perform.
Today, we successfully argued that a plumber travelling to stop sewage leaking into a home was an emergency capable of being a special reason.
Unfortunately, the client did not keep his licence on this occasion as the court decided that he had not fully explored other ways of getting to the emergency other than driving while over the drink driving limit. Had he done so, it appears that he would have kept his driving licence.
This just goes to show that "emergency" is not a fixed term and that there may be room for further development of the law on this point.