The A40 is currently closed both ways due to a serious accident between B4328 (Llanboidy Roundabout) and A478 (Penblewin Roundabout).
The closure is affecting traffic between St Clears and Haverfordwest.
The road is likely to be closed for some time.
Diversion: Local for light vehicles. HGVs to leave A40 at St Clears and use A477 and A4076 to Haverfordwest