Calls are growing for restrictions on young drivers after eight people died in separate car crashes within four days in Wales.
The scene of the crash near Newtown where three teenagers died
All the dead in the three accidents were aged between 16 and 20.
The exact circumstances are not known and will be determined at inquests.
But the AA Motoring Trust wants young people's licences to warn about driving at night with passengers. And a coroner suggests the young could be barred from using powerful cars.
The first accident was on Wednesday when Natalie Malpas, 20, and her brother Mark, 16, as well as brothers Gavin and Aaron Matthews, 19 and 16 - died in Ammanford, Carmarthenshire.
Then early on Saturday three teenage boys - Paul Kennedy, Lee Challoner, both 17, and Daniel Lister, 16 - were killed in a crash near Newtown, Powys.
Seven hours later, driver Michael Anthony Waters, 20, died in an accident with another car in Penclawdd, Swansea.
(L-R) Paul Kennedy, Lee Challoner, and Daniel Lister died near Newtown
Andrew Howard of the AA Motoring Trust said many other countries put curfews on young drivers or limited the number of passengers they could carry.
Under-21-year-olds make up 7% of drivers, but are involved in 12% of accidents
20% of under-21-year-olds have an accident in their first year of driving
Most young drivers' accidents are late at night and with other youngsters in the car
Source: AA Motoring Trust
"The trouble is that here in Britain we really don't have the police enforcement resources at the moment to be able to do this as well as deal with all their other priorities.
"So what we've suggested is that young drivers should have a code attached to their licence which... makes it very clear that the courts and the police will treat more seriously any motoring offences that they commit."
The Royal Society for the Prevention of Accidents (Rospa) offers a voluntary agreement which parents can make with their children highlighting driving at night, carrying friends, alcohol and drugs, mobile phones, speed and seatbelts.
"Parents are in a wonderful position to enforce this if they are paying for the young person's car or if it's the family car they are using," said Linda Morrison, of Rospa.
Marc Malpas and Aaron Matthews: two of the four Ammanford victims
Also speaking generally about cutting the number of accidents involving young people, Pembrokeshire coroner Michael Howells suggested newly-qualified drivers could be banned from using cars above a certain size of engine.
"What is increasingly occurring is these multiple fatality accidents," said Mr Howells.
He said even when young drivers were sober, "they have a car full of people, and because they are inexperienced the extra load perhaps makes the car more difficult to control."