NEW housing developments through Lower Penarth and Sully may result in nearly 4,000 more vehicles using the B4267 every day by 2026, it has been claimed.

The Barry to Cardiff Link Road Group has said the number of planning applications already approved in the area - as well as a number still in the pipeline - will have a dramatic impact on traffic.

The group has claimed the only alternative would be if the Welsh Government complete the Barry to Cardiff link road with access into adjoining communities, saying this would improve access for Wimpy Homes Cog estate, which already has planning permission for 540 houses, with another 300 houses also planned.

The Welsh Government itself owns the land overlooking the sea at Cosmeston, where 576 houses are planned.

There are a further 145 houses to be built near Oak Court in Lower Penarth.

Rod Harrod, the chairman of the Barry to Cardiff Link Road Group, said: “Government statistics estimate there are 1.4 cars per house so with 1,561 houses there could be over 2,000 more car journeys daily in the area.

With most people travelling back and forth in the same day, conservatively traffic on the Penarth to Sully to Merrie Harrier road (B4267) could rise by around 4,000 more trips every day.

“These figures are not scare stories. The current congestion is there to be seen.

“Any changes will take at least five years to implement.

“Even without the extra 300 Wimpy homes there are already 80 new homes built at St Josephs on Sully Road and 298 planned for Llandough.

“They will all converge on the Merrie Harrier junction.”

A study carried out in 2013 - before most of the new developments were planned - predicted the junction would be 400 per cent over capacity by 2026.

The new Link Road group has been formed to engage with representatives of all surrounding areas.

Cllr Neil Moore, leader of the Vale of Glamorgan Council, said: “The council’s cabinet recently agreed to consider undertaking further work on the WelTAG Stage 2 assessment for improving strategic transport in Dinas Powys. Unfortunately, the recent Welsh Government Transport grant funding announcement for 2019/20 did not make any monies available for this particular project. Therefore my officers are currently investigating whether there are any alternative sources of funding available to complete this Stage 2 work.”

Mr Harrod said: “This should be something for all the people of all the Eastern Vale.

“Each area should have its own group.

“We’re asking councillors and officials to consider the domino benefits and detriments of the several routes proposed – not just one."

He also emphasised that no particular route for a new relief road was preferred, saying: “It will inevitably require compromise.

“But we want to make sure the final choice will stand firm when the Welsh Government assess the application.”