Simon Hart MP is joining forces with a local community council to campaign for a new road junction to be made safer.
The Pendine turn off at the new Red Roses by-pass is extremely sharp and is on a very fast section of road.
There are also no signs to Pendine – meaning that traffic for the busy resort is missing the junction and ending up in Amroth or doing U-turns in Llanteg.
"This new stretch of road is a fantastic improvement for the communities of Llandowror and Red Roses but we have got a few teething issues," said Mr Hart.
"I have driven it myself and if you are coming from the St Clears direction and want to turn left to get to Red Roses and Pendine it is extremely hair-raising.
"The junction is practically 90 degrees and it comes at the end of a very fast downhill section. You have to slow right down to take the turning safely and traffic coming down behind you has to brake hard. The junction at Llandowror has a filter lane and that is what is needed at Red Roses too."
Mr Hart raised concerns about the junction with Welsh Transport Minister Edwina Hart last November. Following further lobbying by Eglwys Cymmin Community Council, an additional advance warning sign has been put in place and Mrs Hart has agreed that the situation will be monitored.
Mr Hart added: "I stood at the junction for 20 minutes one Friday morning and counted 40 cars in twenty minutes using the junction.
"I also saw three lorries carrying jalopy cars going to the races in Pendine who missed the junction and had to turn back."
Pendine resident Rebecca Griffiths said: "I don't think the new by-pass is on sat navs yet and Pendine is not signposted so our last three sets of guests have all missed the junction and ended up in Amroth."
Mr Hart added: "Pendine is a busy resort with jalopy races, events on the beach such as the Hot Rods, and the Museum of Speed. It desperately needs to be properly signposted at the new Red Roses junction."
Simon Hart MP
House of Commons
15, St John St
or 0207 219 3000