Drivers found guilty of causing death while texting on their mobile phones, reading a map or eating at the wheel now face a possible jail sentence under laws that come into force today.
Under the legislation for the new offence of causing death by careless driving, motorists who kill while distracted could be imprisoned for up to five years.
Prolonged use of a mobile phone to send and read texts could carry a sentence of up to seven years.
Previously, drivers who caused a fatal accident by being distracted by such activities as applying make-up escaped with a fine.
The Sentencing Guidelines Council announced the changes to law in July.