This junction is appalling badly designed. The only thought behind it appears to be how to maximise traffic flows on the A4040. The weird junction with the high street proper just causes confusion and near-misses. The roundabout is notorious for collisions, and facilities for pedestrians are poor. Facilities for cyclists are non-existent. It is a major barrier to cycling.
The junction should be redesigned, taking into consideration all road users and traffic flows over a wide area with a view to reducing conflicts. For example, consider closing roads to motor traffic so as to simplify the situation and improve permeability for walking and cycling. Motor traffic on the high street (which is looking run down) is bad for trade.