A48 to Camarthen, A40 to St. Clears, Haverfordwest and Fishguard.
Follow the M4 into Wales across the second Severn crossing. (Toll in 2008 is £5.30 for a car.) The motorway terminates at Cross Hands.
Here, take the A48, a dual carriageway, signed to Camarthen. (Just after the end of the motorway there is a service station with a Little Chef and McDonalds.)
At Camarthen, take the A40, a dual carriageway, signed to Haverfordwest and Fishguard (in Welsh, Hwlffordd and Abergwaun).
The A40 bypasses Camarthen and then reaches St. Clears, where it becomes single carriageway.
The A40 bypasses Haverfordwest - Fishguard is clearly signed.
On entering Fishguard, pass the 30 mph signs where, on the left, a new housing estate is being built, and Avon House is about half a mile on the left, just after a petrol station - the first B&B.
We usually reckon that it takes about an hour from Camarthen to Fishguard - you may be lucky and knock off 10 minutes if there are no heavy lorries or caravans to slow you down!