The Department for Transport says its "disappointed" that 4,000 members of staff have decided to strike today.
The PCS union says members will hold 15 minute demonstrations across Wales.
We are disappointed that the PCS union have decided to take industrial action while we are still engaged in consultation with them about their concerns over changes within the department.
Contingency plans are in place to ensure delivery of essential services to the public continues throughout the planned strike action.
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There will be heavy and blustery showers throughout the evening, with hill snow for some.
South Wales Police were called to reports of an unconscious man at Ten11 on Broad Street in Barry at approximately 2.15am.
The event is part of a UK-wide campaign inspired by the late Jo Cox MP, who aimed to raise awareness of the loneliness crisis.