A police officer whose "irresponsible driving" left a colleague with severe brain damage has admitted careless driving.
Pc Ian Thompson was driving a marked police car at 75mph in a 40mph zone when he jumped a red light, crashing into a taxi which was crossing a dual carriageway in Basildon.
Reece Clarke, a special constable who was travelling in the passenger seat, suffered "devastating" injuries, Ipswich Crown Court heard. The taxi driver was also seriously injured.
Prosecutor Michael Crimp said: "A reasonable and prudent driver would not approach that junction at 75mph - he gave himself no opportunity to cope with any hazards."
Thompson was responding to an emergency shortly before midnight on July 24 last year.
He claimed he feared another officer's life was "potentially in danger", but the court heard he might have exaggerated the seriousness of the emergency.
The 31-year-old officer, based in Wickford, Essex, had been charged with dangerous driving. He denied that offence but today admitted the lesser charge of careless driving.
Mr Crimp said that, after consultation with Mr Clarke's family, this plea was acceptable and a trial on the original charge would not proceed.
Mr Clarke, from Shoebury, was based in Billericay and Wickford and was 19 at the time. He has required intensive rehabilitation since the incident.
Mr Crimp said: "The awful consequences of (Thompson) driving as he did are shown graphically in photographs of the aftermath."
He added the prosecution did not "necessarily accept" that the driving had not been dangerous, but he said it was not in the public interest for the trial to proceed.
He said: "We have given due regard to the views of the taxi driver who was badly injured and to the family of the passenger who was very seriously injured."
Allan Compton, mitigating, said Thompson had been responding to a genuine and unusual emergency involving a prisoner at Basildon police station.
The station was "lightly manned" at that time of night but was holding a large number of people in its cells.
"It was a type of emergency he had never before experienced in his career," Mr Compton said.
He added that the phasing of the lights may not have normal safety margins built in.
"He regularly visits Reece Clarke and that is something Reece gets some comfort from," he said. "He will continue to do whatever he can to help the Clarke family."
Judge David Goodin ordered Thompson to pay a fine of £250 and said three penalty points would be added to his driving licence.
He must also pay £85 in legal costs and a £15 victim surcharge.
The judge said the prosecution had taken into account many factors including the "generosity" of Wendy Clarke, speaking on behalf of her son, in reaching its decision to not proceed with the charge of dangerous driving.
He added that he could not take into account the "very serious" injuries suffered by the taxi driver and the "devastating" injuries of Mr Clarke when passing sentence.
But he said Thompson's behaviour had been "irresponsible and wrong".
"You were going to a police station where, by definition, there were a number of police officers and custody staff who could deal with the emergency," he added.
"You drove very fast indeed. There is no question of the red mist descending - you were responding in what you believed to be a proportionate way but it wasn't.
"You drove at excessive speed in a town centre on a very, very busy intersection."
Thompson, who was placed on restricted duties after the crash, will now face disciplinary proceedings.