Careless driving:
�...if the standard of driving falls below that which would normally be expected of a careful and competent driver�
Dangerous driving:
�...if the standard of driving falls far below that which would normally be expected of a careful and competent driver�
Not very helpful, I know, but they are the legal definitions. Despite there being only one word of difference between the two, in practice they are vastly different offences.
Careless driving can be charged where a momentary lapse of concentration occurs. For example, colliding with the rear of a vehicle, pulling out from a side road and causing a collision. Note, however, that although usually charged following an accident, an accident does not have to take place for the offence to be proved.
Dangerous driving is usually charged where a sustained and deliberate act of bad driving occurs. For example following a police chase.
The usual penalty for careless driving is a fine of one week�s income and between 3 and 9 penalty points (depending on the nature of the carelessness).
Dangerous driving can result in up to two years imprisonment. It also carries a mandatory ban of 12 months minimum (unless there are special reasons for not doing so) and an extended re-test must be taken before driving can resume.