The amount of traffic using the A40 has increased by more than a quarter in the last six years.

Monitoring stations on the main artery from St Clears to Fishguard have also revealed that traffic is increasing almost twice as fast as on other roads.

The figures have been highlighted in a short debate at the Welsh Assembly by Preseli Pembrokeshire AM Paul Davies.

"I spoke about the need to dual the A40 in a short debate because it is such an important matter to me and because the First Minister has refused point blank to dual the road."

Mr Davies revealed that more than 14,500 cars and lorries were counted on the road to the west of Canaston Bridge every day.

The Department for Transport guidelines state that a standard single two-lane carriageway like the A40 should only carry up to 13,000 cars and lorries a day.

"How can Rhodri Morgan say the A40 is not busy enough to dual when there is already more traffic than the upper limit set by Government?"

Analysis of the data from 2000 to 2006 also showed an annual average increase in traffic of 4.1% across the five monitoring stations and a total growth in traffic of 27%.

Mr Davies described the planned improvements to the road at Robeston Wathen and Slebech as "no more than sticking plaster" which weren't addressing the main problem.

"Dualling the A40 would undoubtedly reduce the number of accidents, injuries and deaths," he added. "The people of Pembrokeshire deserve no less."