The court heard that shortly before 04:30 BST two police officers in an unmarked car were heading westbound on the A48 Cross Hands at about 70mph (113km/h) when a black BMW M 140i overtook them at a speed in excess of 100mph.
Prosecutor Caitlin Brazel said the police officers accelerated their car to the maximum speed – reaching a speed of 120mph – but still lost ground on Dangerfield’s vehicle.
She said officers continued to head westbound before coming across debris in the dual carriageway and finding a badly damaged Toyota on the nearside verge.
The two female passengers in the back of the taxi were able to exit the car but the driver was unresponsive and trapped inside.
The court heard that as the police officers tended to the taxi driver, a motorist who had been driving behind the police car when they were both overtaken by the BMW arrived on the scene.
He went over to the BMW which had come to rest on the opposite carriageway.
Brazel said the BMW was “extensively damaged” and that when the motorist “pulled back the deployed airbag he expected to find the driver dead”, instead he found Dangerfield chatting on his phone.
The court heard firefighters freed the taxi driver, and he was taken to University Hospital of Wales. He underwent a number of procedures and operations before being discharged on 1 February.
He was deemed medically unfit to drive meaning he could not return to work.
Brazel said download data obtained from the BMW’s airbag showed the car had been travelling at 141.6mph (228km/h) at the point of collision, but a forensic crash investigator who examined tyre marks at the scene concluded the vehicle had been travelling in excess of that speed prior to the collision.