Transport for Wales have urged people to only use trains for essential travel, as tailbacks of up to three miles are reported heading to Barry Island.
Road users have reported tailbacks from Barry Island, as far back as the McDonald's Roundabout on Cardiff Road - approximately three miles away from the famous coastal resort.
Pictures on social media have shown long delays for visitors, as they head to the beach whilst temperatures reach 27 degrees in the County.
Train users are also reporting rail services are between Cardiff and Barry Island do not conform to current social distancing measures, with Transport for Wales urging for nothing but essential travel.
South Wales Police neighbourhood policing officers yesterday estimated 20-25,000 visited Whitmore Bay on Wednesday alone, as temperatures reached just 23 degrees.
Leyton Powell, Safety and Assurance Director at Transport for Wales said "The safety of customers and colleagues is our top priority and we're asking everyone to only use public transport for essential travel and where there are no other alternatives."
"Our capacity has been massively reduced due to social distancing measures and we must maintain a safe space for those key workers using our services."