Police said a 28-year-old man was pronounced dead following a collision just after 4pm on Friday (July 13) on the A65 between Clapham and Ingleton, just north of the turn off to Bentham.
A white, flatbed truck, which was converted into a home-made campervan, was travelling towards Ingleton and collided with a Peugeot car travelling in the opposite direction.
The man who died was a passenger in the Peugeot. Police said he was from Wigan.
The driver of the Peugeot, a 21-year-old woman, also from Wigan, was taken to hospital but later discharged.
The driver of the campervan conversion, a 28-year-old man from the Halifax area, was arrested at the scene of the crash on suspicion of causing death by dangerous driving and driving while unfit through drink/ drugs.
Three other men who were travelling in the campervan conversion sustained minor injuries.
A third vehicle, a white, decommissioned ambulance, believed to be in convoy with the campervan, left the scene of the incident.
Officers followed the vehicle and pursued it in the direction of Skipton before it collided with the barrier of a level crossing near Kildwick and came to rest on the train tracks.
The driver and sole occupant of the decommissioned ambulance, a 41-year-old man from Halifax, ran from the vehicle but was found a short time later with the assistance of air support from the National Police Air Service.
He was arrested and taken into custody. The train line was closed following the incident until the vehicle was recovered.
Both drivers remain in police custody.
A North Yorkshire Police spokesman, said: "Police are appealing to anyone with any dash-cam footage or who saw either the converted campervan or the decommissioned ambulance travelling along the A65 prior to the crash and to anyone who witnessed the crash, to contact them if they have not already done so.
"The converted campervan was quite distinctive due to the crudeness of its conversion which is described as a flatbed truck converted into a camper."The decommissioned ambulance also used its blue lights during its journey towards Skipton.
"Officers are appealing to anyone who may have seen the “ambulance” which also had livery on the side of it, or has any dash-cam footage of its journey, to contact them. Members of the public may have believed it was a real ambulance due to the use of its blue lights."
Anyone with any information is asked to contact North Yorkshire Police on 101, quoting reference number 12180126976
The A65 was closed while emergency services dealt with the collision, to allow collision investigators to examine the scene, for the vehicles to be recovered, and to allow the road to be cleared and swept. It reopened fully at 8.30am today. (Sat July 14)