This offence is committed when the accused's driving falls below the standard expected of a reasonable, prudent and competent driver in all the circumstances of the case.
The test of whether the standard of driving has fallen below the required standard is objective. It applies both when the manner of driving in question is deliberate and when it occurs as a result of incompetence, inadvertence or inexperience.
Occasionally an accident occurs but there is no evidence of any mechanical defect, illness of the driver or other explanation to account for why the accident happened. In these cases, a charge of careless driving may be successfully defended on the basis that there is no culpability. The case for the prosecution may be put on the basis that there is a very strong inference that the defendant was driving below the standard expected of a reasonable, prudent and competent driver because of, for example, the fact that a collision resulted.
The above examples are merely indicative of what can amount to careless driving.