Police have issued CCTV images of two women seen with a man who was later killed as he walked along the M62.
Officers want to find the women, who were socialising with 24-year-old Ben Lloyd in Pontefract shortly before he was hit by a car on the motorway near the town.
PC Carl Sapsford, of the major collision enquiry team, said: “As part of our enquiries we have been working to build up a picture of Ben’s movements on the night and would like to speak to two women who we believe were friends of his but not known to other friends or relatives who we have spoken to.
“I really do want to stress we only want to speak to them as witnesses to help us build up a picture of Ben’s movements and demeanour.”
Ben, from Barnsley, had been on a night out in Pontefract on Friday, December 20.
He is believed to have left the Malt Shovel pub with a group of people at about 1.30am the following morning and walked through the Corn Market to arrive at the Horse Vaults at 1.35am.
He then got into a silver Vauxhall Vectra taxi with the two women at about 2am.
The cab stopped at the Natwest Bank on Ropergate and then drove to the Smawthorn area of Castleford where the women were dropped off.
It is then believed to have carried on to the BP garage on Park Road, Glasshoughton, where Ben is thought to have got out.
He was killed after being hit by a Volkswagen Polo at about 3.42am on the westbound carriageway of the M62.
PC Sapsford added: “We are continuing to investigate the circumstances leading up to Ben’s tragic death and would like to speak to the group pictured in these images who we know were with Ben before he left Pontefract.
“A great deal of work has been underway to piece together Ben’s movements on the night and we are continuing our investigations.”
The Independent Police Complaints Commission is investigating West Yorkshire Police’s handling of calls before Ben’s death.
It is looking at what action was taken and whether national guidelines and the force’s own policies were followed.