They want to hear from anyone who saw two white transit vans traveling towards Harrogate, through Killinghall and on to the A61 towards Ripon.
The two vans were seen driving along the road at around 10.30am, when police received reports from concerned motorists about their manner of driving.
If you believe you saw the two vans, please contact North Yorkshire Police on 101, select option 2 and ask for Traffic Constable Steve James. Or email firstname.lastname@example.org
Please quote reference 12140170334 when passing on information about this incident.