Never been on that road Mex but it looks long and remote over in Suffolk?
If we are allowed A roads, I think the West section of the A66 was once voted the UK's worst road?
It's single lane in many places, so if you get stuck behind a tractor or truck, you're knackered - it's a busy road so the other lane is usually full so no way of overtaking.
But for motorways, I'm a bit surprised the M65 hasn't been mentioned. It reduces from 3 to 2 lanes in quite a few places with little warning. I've seen a few accidents where drivers are quickly trying to get into lane 2 when lane 3 is disappearing in front of them.