Mooez Masroor Subhani, 33, and Dr Aimen Rafiq, 27, were fatally injured when their car crashed into trees at the roadside in August last year.
It was acknowledged that the exact reason for the driver losing control of his car will never be known.
Coroner Chris Long was told that Mooez was driving the vehicle on August 12, 2021 when driving conditions were good.
It is thought Mooez may have made a sudden pull on the steering wheel and lost control of the vehicle.
The couple from Stepping Lane, Derby, both originally from Pakistan, died at the scene - Mooez from a traumatic brain injury and Dr Rafiq from multiple traumatic injuries with a severe cerebral injury. They were identified by their fingerprints.
Dashcam evidence was shown in the court which showed how their car, a Mazda 3, veered at speed across the motorway lanes before crashing to a halt.
The court was told toxicology reports showed "no significant findings" regarding the driver and his heart was found to be normal.
PC Barry Moore, forensic police investigator with Lancashire Constabulary, attended the scene one hour after the crash. The northbound carriageway had been closed and PC Moore said: " There was four tyre marks crossing from lane two into lane one."
The marks continued onto a T-junction at a works exit and on the verge.
Both Mooez and front seat passenger Aimen were wearing seat belts and there were no mechanical defects found on the car and no defects on the carriageway which could have contributed to the accident., PC Moore continued: "The Mazda lost control on lane three. It was travelling in excess of the speed limit."
PC Moore suggested a "sudden harsh input of steering" could have caused the rear of the vehicle to move out which would require correcting. But the car continued to move across the lanes and was out of control. He said: "It's unlikely the driver would have been able recover it at that point."
The car hit trees and its roof peeled back. It had continued to rotate round on the carriageway verge. P.C. Moore said it had not been possible to identify the cause of the loss of control but it was likely to be caused by suddden or harsh steering.
Details of statements from three witnesses were read out in court. The first witness Charles Barton was driving north in lane one and had "suddenly become aware of a red car passing close to the driver's door. The vehicle began to skid in front of them turning so the passenger door was facing him. The car accelerated towards the works exit."
The court was told Mr Barton believed the car had gone down the access road to that exit and continued his journey home. Shaken by the experience he later checked his dashcam and realised the vehicle had smashed into trees. He contacted police providing them with the dashcam footage which was shown in court.
Another driver witnessed the accident and stopped on the hard shoulder to ring emergency services, while a third provided evidence that the Mazda picked up speed and came across the motorway out of control and hit the bank. When the North West Ambulance team arrived the couple showed no signs of life
.The coroner said: "The evidence supports the vehicle was either steered suddenly or harshly and it led to loss of control of the vehicle. "
He said that after colliding with the trees the couple's injuries were "unsurvivable."
The accident occurred at marker post 365 between Preston and Lancaster and the coroner concluded that the cause of both deaths was a road traffic collision. He asked for his condolences to be passed to the family and friends of the couple and said: "It really is a tragic loss and I'm very, very sorry."
* Folllowing the tragedy colleagues of Moeez at the University of Liverpool set up a GoFundMe fundraising appeal for road safety charity Brake.The appeal noted that Mooez had joined the university's Department of Public Health, Policy and Systems in January 2021.
A statement by colleague Chris Kypridemos, posted on the university website noted: "Moeez was an intelligent, capable, diligent and valuable colleague. But above all, he was a warm, kind and gentle soul. His love for data science and his enthusiasm to further use and develop his skills in improving health through research were embodied in his diligent work and his interactions with the team, despite the challenges imposed by joining a new post in a new group and university during the pandemic."