Jonathan Ball died after his Skoda Yeti car collided with the back of a broken down DAF tipper truck on the Stanningley Bypass near to Richardshaw Lane just before 7pm on Saturday November 24.
West Yorkshire Police have today said they want to speak to the driver of a black Ford Focus that was travelling behind Mr Ball's car.
Det Sgt Fiona Hoodless of the Major Collision Enquiry Team, said: “We are continuing to investigate this collision and are particularly keen to trace the driver of a black Ford Focus who we know was travelling behind the Yeti and who may well have witnessed the collision.
“I would ask this driver to come forwards and speak with us as he or she may well have important information which could help the investigation."
The driver of the truck was not in his vehicle at the time and was not injured, added a police spokesperson who also said enquiries remain ongoing into the collision.
The driver or anyone else with any information who police have not yet spoken to is asked to contact the Major Collision Enquiry Team via 101 quoting log number 1581 of November 24.