The precise cause of a crash which killed a mother, her young daughter and another man cannot be determined, an inquest has heard.
Tracy Evans, 39, of the Cae Garw traveller community near Pyle, and her daughter Scarlet, 4, died in the crash but her 12-year-old daughter survived.
Their car collided with a Rover driven by Ieuan Roberts, 61, of Kenfig Hill, on the A48 near Margam Park last March.
The Neath coroner recorded verdicts of accidental death in all three cases.
Mrs Evans' other daughter Mari Evans, 12, survived the crash.
Police told the inquest their investigation was "hampered" by her family's refusal to allow them to speak to her.
Investigating officer Tony Rees, of South Wales Police, said: "Investigations have been somewhat hampered by the family of Tracy Evans.
"As a result we have not been given the opportunity to interview the surviving daughter."
Pc Rees said that there was no record of Mrs Evans having ever held a driving licence and the Ford Mondeo car which she was driving was registered to an address that did not exist.
But again he said her family had refused to help police inquiries.
The court was told Mrs Evans and Mr Roberts died from multiple injuries at the scene, but the two children were taken to the Princess of Wales Hospital, Bridgend.
Scarlet Evans died from head injuries a short time later.
Motorist Neville Williams told the hearing that at about 1545 BST he was driving on the A48 trunk road from Bridgend towards Port Talbot.
He said as he approached the junction with Old Park Road Mrs Evans' Mondeo overtook him and returned to the correct lane before disappearing over the brow of a hill.
"I could not see the actual collision but there was a tremendous bang and I saw the Mondeo go up in the air. It twisted sideways and landed in a hedge."
A police investigation showed the Mondeo collided with Mr Roberts' Rover, which had encroached about 40cm (16in) into the oncoming lane.
There were no defects on either vehicle, but both were damaged to such an extent it was not possible to calculate the speeds they were travelling.
Recording his verdicts, coroner Dr David Osborne said: "It's apparent that these two vehicles were travelling in opposite directions in daylight on a road surface that was in good condition when they collided virtually head-on.
"The precise mechanism of the collision has not been discovered."