The Dublin Circuit Criminal Court has been told the bus accident on Wellington Quay in which five people died three years could have happened in a matter of seconds.
A technician from Volvo, also told the court he was aware of other cases in which had been suggested that a power surge had taken place on a bus.
51-year-old bus driver Kenneth Henvey, from Palmerstown in Dublin, has pleaded not guilty to dangerous driving causing the deaths of five people on 21 February 2004.
Garda accident investigator, Tony Kelly gave evidence that tests were carried out on the acceleration and steering in Mr Henvey's bus at Wellington Quay.
Garda Kelly said the bus travelled just under 29 metres from the time it set off until it stopped just outside the Clarence Hotel.
The tests and video footage from a CCTV camera outside the hotel he said, showed this journey took on average, 8.63 seconds.
Although he said the tests did not take account of Mr Henvey's bus mounting the kerb or hitting street furniture.
Garda Kelly said he would have expected the driver to react to what happened in just over two seconds.
He said he had never come across the phenomenon of a sudden engine or power surge.
But Terence Baker an engineer from Volvo, who makes buses for Dublin Bus, said he was aware of other cases in which it had been suggested that a power surge had taken place in a bus.
Mr Baker said these other cases involved vehicles older than the bus driven by Mr Henvey.
