THE Cwmgwili man killed in a fatal collision with a speeding police car "must have seen" the oncoming vehicle, according to accident investigators.

Roger Bowen, aged 55, died when his car was hit by the Dyfed Powys Police patrol vehicle as he turned across the eastbound carriageway of the A48 at the notorious Cwmgwili Junction at 9pm on March 3, 2009.

Mr Bowen's Vauxhall Astra "somersaulted" some 250-feet along the carriageway after being struck side-on by the Volvo T5 estate at 76mph.

Mr Bowen was thrown from the vehicle during the smash and died instantly. His 17-year-old son Ashley, a backseat passenger, suffered serious and life-threatening injuries, but has since recovered.

Crash investigators told an inquest at Llanelli that the primary cause of the crash was "driver error".

PC Keith Harding - the officer at the wheel during the fatal crash - told the inquest that Mr Bowen's car was stationary as he approached the junction at speeds as high as 96mph with blue lights flashing.

"I saw the car at the junction," said PC Harding, a Grade One Advanced Police Driver with 19 years experience. "I could not see it moving and assumed it was on stop.

"I was 20 to 30 metres from the junction when the car pulled out.

"I had so little time to react. I saw the car pulling out and then there was an almighty bang."

PC Harding told the hearing that he had spent the evening carrying out speed checks on vehicles passing the Cross Hands Business Park slip road and had set off in pursuit of a "hot hatch, boy racer-type car" which he had clocked at 88 mph.

PC Harding admitted regularly reaching 110mph when chasing speeding vehicles along the A48 and was certainly travelling over 100mph moments before the smash.

Robert Harrison, representing Mr Bowen's family, asked PC Harding why he had approached such "a dangerous road" at such high speed and why he had not switched on his sirens as well as his blue lights.

"I eased off as I approach the brow of the hill," said PC Harding, adding he had not used sirens because the traffic was light and he had not wanted to cause a nuisance to nearby homes.

Mr Bowen's son Ashley confirmed in his statement that his father had come to a halt at the junction as the pair returned from a swimming lesson in Llanelli.

"We turned onto the junction for Cwmgwili and stopped on the central reservation," said Ashley, who was sitting in the rear seat playing a computer game at the time of the smash.

"He always stopped there. He never took any chances."

Ashley said he sensed the car begin to move across the road when he heard his father swear.

"I looked up and saw bright white lights coming towards me," said Ashley.

"I did not hear anything before the accident just a big bang and that was it."

Road accident investigator PC Richard Jessop told the court that his calculations showed PC Harding's Volvo was travelling between 81mph and 96 mph before the officer applied the brakes.

He calculated that PC Harding was travelling at 76mph at the moment of impact.

"Considering the physical evidence, the primary cause of the accident was an inappropriate manoeuvre by the driver of the Astra," said PC Jessop.

"He must have seen the Volvo as he waited at the junction. "The question of why the driver of the Astra has attempted to cross the carriageway with the Volvo so close remains unknown."

Carmarthenshire coroner John Owen adjourned the hearing to consider all the evidence before reporting back with his conclusions.