South Wales Police say 12 vehicles have been involved in a crash on the A465 between Glynneath and Hiwaun this evening.
One person has been taken to hospital with injuries not believed to be serious.
The road remains closed as emergency services work to clear the area.
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It will become increasingly cloudy with some showery rain at times and heavier downpours by the early hours of the morning.
Russell Wadge, of Baglan Farm in Trimsaran, will appear before Haverfordwest Magistrates Court on Wednesday.
The Tour de France winner was forced to pull out of the Tour de Suisse after a crash during the fourth stage of the competition.