Drivers who cause death by careless driving could face five years in prison under a string of new driving offences announced by the government.
The measures differ slightly in Scotland to reflect Scottish law
They have been tabled as amendments to the Road Safety Bill and would apply in England, Wales and Scotland.
The measures also create a new offence of "causing death when driving while unlicensed, disqualified or uninsured", carrying a sentence of up to two years.
Road charity Brake said the proposals were a "step in the right direction".
BBC transport correspondent Tom Symonds said the new offence of death by careless driving was a toughening of the law that road safety groups had been demanding for a long time.
Current laws mean that someone convicted of death by dangerous driving can be sentenced to 14 years in prison, while the penalty for careless driving has a maximum penalty of a £2,500 fine.
Tom Symonds said: "The problem is, if you kill someone when you've only driven carelessly, then you can't be sent to prison - you can only have a fine.
"This new offence will make it a lot more difficult for people to get away with that lower level of penalty."
The offence of causing death when driving while unlicensed, disqualified or uninsured, meanwhile, does not relate to a standard of driving.
It means an illegal motorist could be convicted if, for example, they hit and killed a pedestrian through no driving fault of their own.
"Under the new proposals, a driver on the road illegally would be liable if, but for his or her presence on the road, the accident and consequent death wouldn't have occurred - even if his or her standard of driving is not at fault," a Home Office spokesperson said.
The new measures also include a statutory definition of careless driving.
Brake spokesperson Aimee Bowen said: "Changes to the system of charges and penalties for driving offences are long overdue.
"All too often we see killer drivers, who devastate families and communities through reckless and selfish behaviour behind the wheel, getting away with little more than a fine."
But, while welcoming the proposals, she said: "They fail to address the ongoing lack of justice for many drivers who cause serious injury on the roads."
Criminal Justice Minister Fiona MacTaggart told BBC Radio Five Live that the offence of death by careless driving would allow courts to take into account the fatal consequence of careless driving.
"At present you can get such a sentence if someone is drunk, but you can't if someone is sober and just driving carelessly," she said.
"What we're doing is - we're on the side of the victim, we're making sure that people who kill on the road can get proper prison sentences.
"We're making sure that if someone kills when they're driving carelessly - even if they didn't mean to - then they can be sent to prison."
Tony Leigh's 14-year-old daughter Jessica was killed instantly by a motorist speeding at 60mph.
He told Five Live: "[The driver] went to court and pleaded not guilty and then, when he finally got into court after about a year-and-a-half, all he got was a £300 fine and six penalty points."
Mr Leigh said he believed the punishment - after hearing the graphic details of his daughter's death in court - was "horrendous" in its inadequacy.
But he said the new measures would address his concerns: "In a car, I must admit, you don't go out on that day saying I'm going to run someone over.
"So up to five years in his case - where it was a tragic accident, which could have been avoided if he had been driving more sensibly - then I reckon five years is quite good."