Traffic officers from North Yorkshire Police are appealing for witnesses following a fatal road accident on the A162 near South Milford.
It happened at about 6.15am on Wednesday, August 24 and involved a black lorry and a blue Yamaha YZF R6 08 motorcycle.
At the time of the collision both vehicles were travelling southbound on the A162, towards the A1, just after an unclassified road junction.
North Yorkshire Police said the motorcycle struck the nearside of the lorry and left the road.
The rider of the motorcycle, a man aged 46 from the South Yorkshire area, was pronounced dead at the scene of the collision.
The 44-year-old Tadcaster man who was driving the lorry has been arrested in connection with the incident.
The road between the roundabouts for South Milford and Sherburn was closed for about four and a half hours.
Traffic Constable Roger Walker, of North Yorkshire Police’s Roads Policing Group, said: “At the time of the collision there was patchy fog in the area.
“Although it is too early to say if this was a factor in this collision, I urge people to take extra care on the roads and slow down when visibility and road conditions are poor.
“I am appealing to anyone who witnessed the manner of driving of either vehicle prior to the incident, or the road conditions at the time of the collision, to contact the police as I need to speak to them as a matter of urgency.”
Anyone with information about the incident should contact TC Roger Walker on 0845 60 60 24 7 quoting reference number 12110143328. Or call Crimestoppers anonymously on 0800 555 111.