A diabetic driver blacked out at the wheel seconds before killing a district nurse who was walking on a pavement with her husband, a court has heard.
The couple were taking their regular walk when the car crashed into them
Suzanne Meredith, 54, was killed instantly and her lecturer husband was injured in the crash near their home in Sully, Vale of Glamorgan, last summer.
Phillip Willey, 45, of Barry, denies causing death by dangerous driving.
He has been accused of failing to control his blood sugar levels during his journey leading to the blackout.
Mrs Meredith and her husband Julian were holding hands on their regular evening walk through the village of Sully, near Cardiff, when Mr Willey's Subaru Legacy came towards them at speed.
Cardiff Crown Court heard lecturer Mr Meredith, 52, shouted: "My God, it's going to hit us" before the car mounted the pavement on the B4267 Lavernock Road.
Mrs Meredith, described as a devoted wife by her three children, died instantly from head and chest injuries.
Her husband told police: "There was no time to take avoiding action. After the collision I was calling out for Sue - but I got no answer."
The court heard that Willey fell unconscious due to a diabetic attack just before the crash.
Prosecutor Marion Lewis told the jury he was supposed to have a sugary snack on hand in his car in case of such an attack.
"He knew what he had to do but chose not to do it," she said.
"He was driving dangerously on the day of the collision and he is criminally responsible."
Eyewitnesses told the court of Mr Willey's "psychotic, terrible and dangerous" driving before the accident.
Motorist Ahmed Shah, who was driving immediately behind Mr Willey, told the court he was stopping and starting then swerving from one side of the road to the other.
The court heard Mr Willey had a diabetic attack
Another driver told police he saw Mr Willey "swerving like a Formula One driver trying to warm his tyres up".
He said: "It was like the car was being driven by a joyrider. Through my rear mirror I could see smoke coming from the tyres."
The jury also heard that Mr Willey did not attend vital regular checkups to deal with his diabetes, which was diagnosed 10 years before the fatal crash.
Miss Lewis said that he had not informed his insurance company of his diabetes, nor the DVLA and he failed to regularly check his blood sugar levels.
"This is someone who was not managing his illness properly and was trying to ignore his condition," she told the court.
The trial continues.