Motorists and other road users are being urged to be vigilant after Met Éireann issued a status yellow alert warning of dense fog in parts of Carlow overnight and early on Thursday morning.
The national warning, which came into effect at 10pm on Wednesday, remains valid until 11am on Thursday.
"Dense fog in many areas overnight and for a time on Thursday morning," it states.
AA Roadwatch is urging motorists to drive with extra care and to use their fog lights if they encounter fog while the warning is in place.
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