A-Class Driving School's Online Tutorial - Avonmouth Test Centre - The Three Large Roundabouts in Avonmouth & the yellow box on St. Andrew's road
If you turn right out of the test centre, right at the end of that road, then left at the lights you'll find yourself here. You'll come across it within the first 5 minutes of the test if the roads are clear and traffic lights are green. There are three very large, traffic light controlled spiral roundabouts all within minutes of each other. You could find yourself following signs for the independent driving section too to add to your woes.
This video shows you how to negotiate these roundabouts if heading towards Bristol and the A4. If you're heading into Shirehampton at the third roundabout, the only difference is that rather taking the third exit, it's the second, so stay in the left lane all the way around.
So, that's on the way out of Avonmouth, what about the way back? Yes, it's possible you'll be coming back here, or seeing it for the first time towards the end of the exam. The video below shows you shows you how to deal with them coming from Shirehampton, which is slightly harder than from The Portway (A4).
It's also worth pointing out the yellow box outside the fire station on St Andrews Road, just before the first large roundabout.