A driving test examiner accused of murdering his wife by steering off a motorway has claimed to have no memory of the two hours and 40 minutes leading up to the crash.
Ian Walters told jurors he could not think of any "reasonable reason" why his Mitsubishi pick-up truck had ploughed into a line of trees beside the M1 at up to 84mph.
The 51-year-old former bank worker also told Leicester Crown Court that he was devastated when he woke up in hospital and was informed of his wife Tracy's death.
Prosecutors allege that Walters deliberately crashed off the M1 near Markfield, Leicestershire, after his wife demanded a divorce following a string of arguments.
A four-week trial has heard that the couple were returning early from a "make-of-break" week away in Reeth, North Yorkshire, when the pick-up veered off the M1 at about 12.40pm on March 21 last year.
During a second day of evidence, Walters told jurors that his last recollection prior to the crash was seeing a sign for the A1 in Richmond, North Yorkshire, shortly after he visited a petrol station at about 10am.
Answering questions from defence QC Christopher Millington, the former driving instructor, of Tregantle Walk, Swindon, said his next memory was waking up in hospital wearing a surgical halo several days later.
Invited by Mr Millington to comment on CCTV evidence showing the Mitsubishi moments before it crossed the hard shoulder, Walters told the court: "Up until the point where we started to go to the left, everything seems to be perfectly normal.
"I can't explain how it happened. I have no memory of it and I can't come up with any explanation for it.
"I can't think of a reasonable reason why."
Walters, who was badly injured in the crash, insisted that he had no desire or intention to kill himself or his wife.
Asked to describe what was in his mind in terms of the future on the day of the crash, Walters told the court: "We were going home to a nice long-weekend - a good bright future together."
Jurors have heard that Mrs Walters had referred to her marriage as a farce in a text message and complained that her husband made unreasonable sexual demands.
Walters told the court yesterday that he had a higher sex drive than his wife, causing rows which saw their "exciting and very adventurous" sex life decline over time.
During cross-examination by prosecutor Charles Miskin QC, Walters denied that he had adopted a "default position" of claiming not to remember the crash , having earlier told police he could not recall details of a domestic incident.
Rejecting allegations from Mr Miskin that the relationship had become "toxic" and was plainly very difficult, Walters added: "Generally it was a happy relationship punctuated with too many incidents of there being problems.
"We were both quite positive about our future."
Walters told the court yesterday that he regarded his 48-year-old wife, who he married in Cyprus in 2012, as his "world" after the break-up of his previous marriage.
He went on to assert that he had twice fallen asleep at the wheel before leaving his job as a senior credit compliance manager with Barclays in 2003.