Launceston man David Johnathan Holmyard, 26, was remanded in custody in the Supreme Court on Friday after he admitted his guilt at the last minute.

On Thursday, Holmyard pleaded not guilty to the manslaughter of Maureen Ann Flanagan, 54, on Evandale Road at Western Junction on November 7, 2014, in circumstances that amounted to culpable negligence.

This was a confirmation of the not guilty plea he previously entered in the Launceston Magistrates Court in March this year.

Mrs Flanagan died when Holmyard's blue Ford XR6 collided with her Nissan Navara as she turned into her driveway at Western Junction.

A jury was empanelled and opening addresses were yet to start in Launceston.

But on Friday, Holmyard - who was dressed more casually than his shirt and tie from the day before - changed his plea to guilty.

Justice Robert Pearce took Holmyard's plea to the indictment, which included the particulars of the manslaughter charge, and relieved the jury from further attendance.

Holmyard's late guilty plea included admissions that he was affected by alcohol and/or drugs, he drove at an excessive speed in all the circumstances, he failed to drive on the correct side of the road, he failed to maintain proper control of his car, he failed to take reasonable precautions to avoid a collision and he failed to keep a proper lookout.

Crown prosecutor Linda Mason requested an adjournment for the facts to be settled and victim impact statements to be prepared.

She said she anticipated she would be ready to read the Crown facts on Monday.

Defence counsel Mark Doyle said he would ultimately request a pre-sentence report through the Forensic Mental Health Service.

Justice Pearce adjourned proceedings to Monday at 2.15pm.

Outside court, the family of Mrs Flanagan expressed their relief with Holmyard's change of plea.