Ive just witnessed this idiot nearly causing a major collision. So I come off the roundabout heading towards Merthyr Tydfil. The outer lane is closed and coned off. I pull in to the inner lane. This idiot decides to overtake me, a van and then a car who had to brake and swerve to avoid being t-boned. Idiots like this cause accidents and should not be on the road. I hope car insurance companies look at this site!