A woman who drove for almost two miles down the M4 before a fatal crash was almost two and half times the drink drive limit, an inquest heard.
Georgina Coombs, 38, from Cwmbran, also took cocaine before the smash between junctions 26 and 27 of the motorway on 22 February, a hearing was told.
She had driven against vehicles swerving and flashing their lights.
Gwent coroner Caroline Saunders gave the cause of death as multiple injuries from a road traffic collision.
Written evidence described how Ms Coombs had been at a party with family and friends and, following a disagreement, left without telling anyone.
CCTV footage, eyewitness accounts and dashcam footage suggested she had exited at the Tredegar Park turn-off but drove on to the westbound carriageway against the flow of traffic.
The coroner said she was satisfied road signs and markings were "clear and unambiguous" and it was not a "natural or obvious turn to take".
She said Ms Coombs had driven for 1.7 miles (2.8km), with several cars swerving out of her way and flashing their lights before the crash at 22:40 GMT.
Life changing injuries
"It is hard to understand why she did not realise her mistake and pull onto the hard shoulder," the coroner added.
Her car then crashed into BMW driver Dale Jones's vehicle just after he had travelled through the Brynglas tunnels.
He suffered life-changing injuries, the court heard.
The coroner said: "I am of the opinion that the high level of alcohol was the reason that Georgina was driving in this dangerous and fatal manner."
A family tribute read: "Georgina was involved in a tragic accident which has left two children behind and huge hole in the family who are truly devastated.
"Gina will be truly missed by everyone who knew her."