The incident happened in the early hours of Tuesday morning (Jul 28) and involved a green Polaris all-terrain vehicle with a trailer, a white Vauxhall Vivaro van and a black VW Golf.
The Polaris and the Vivaro were both travelling on the southbound carriageway near Thimbleby when they were involved in the crash, while the Golf was on the northbound carriageway when it was struck.
The two men in the Polaris were both seriously injured in the collision. One was pronounced dead shortly after he was taken to hospital by an ambulance. The other is in hospital and has been arrested in connection with the investigation.
Both carriageways of the A19 remained closed until 12pm while the emergency services worked at the scene and to allow a full examination by the Major Collision Investigation Team (MCIT).
The MCIT is urging people to come forward with eyewitness accounts and any dash camera footage from around the time of the incident.
It is believed a HGV may have been travelling on the south-bound carriageway not far behind the Vivaro. Officers need to speak to the driver as a potential key witness.
Anyone with information is asked to call North Yorkshire Police on 101, select option 2, and ask for Marie Williams, or email [email protected], and quote reference number 12210169569.
Alternatively, contact Crimestoppers anonymously on 0800 555 111.