Dyfed-Powys Police is appealing for witnesses and dashcam footage following a collision on the A40 near the Broad Oak crossroads, near Llandeilo, at shortly before 6pm last night (21 July).
The vehicles involved were a grey Toyota Hilux which was towing a trailer, travelling towards Carmarthen and a blue Mercedes A class, which had been driving towards Llandeilo.
A woman was taken to hospital by ambulance with serious injuries, where she remains.
A 57-year-old man was arrested on suspicion of causing serious injury by dangerous driving and remains in police custody.
The road was closed from Dryslwyn crossroads to Broad Oak crossroads while police, fire, ambulance and air ambulance, dealt with the incident.
The road was reopened by 12.30am today.
Anyone with information or dashcam forage that could help officers with their investigation is asked to report it to Dyfed-Powys Police, either online at https://bit.ly/DPPContactOnline, by emailing firstname.lastname@example.org, or by calling 101. If you are deaf, hard of hearing, or speech impaired text the non-emergency number on 07811 311 908. Alternatively, contact the independent charity Crimestoppers anonymously by calling 0800 555111, or visiting crimestoppers-uk.org. Quote reference: DP-20220721-336.