Just to pick up on this line, which shows one of the subtle little bits of ingrained entitlement that is part of the problem:
So what is a safe speed for a dual carriageway, national speed limit road then?
roads don't have safe speeds, conditions do.
The physical parameters of the road (width, bends, visibility, surface, camber etc.) are part of what makes up the conditions, hence classifications of road types and general limits (note the emphasis) but there are other parts too, like weather, and erm... other road users!
If there are a cyclists using the road, for whatever reason, commuting, TT or otherwise that changes the conditions, in the same way it would if there were a herd of cows on the road, or if it was tipping it down or snowing.
That doesn't mean the speed limit for the road is wrong, it is after all a maximum speed allowed under ideal conditions.
The point I'm trying to make is that observing that other users are there, vulnerable users in this case, possibly who might need to overtake other users, or swerve to avoid debris, potholes, or even getting caught by a gust of wind means that you drive accordingly, sometimes that means slowing down, or god forbid...waiting and NOT overtaking until it is safe.
...but if a cyclist decides they are going to swerve across a lane without warning how are you going to miss them? ....
As Epicyclo and others have said, by not passing so close that a small sideways movement means you hit them. Syclist's overtaking other cyclists will not swerve into your lane, they may move further out into their lane to overtake another cyclist.
The only time they can come into conflict is if someone is trying to overtake them in the same lane, and that is pretty much by definition not a safe overtake.
If giving them the correct amount of room to overtake them, ie: over the line into the next lane then your scenario is nullified, or are you suggesting that TTers swerve completely out of lane 1, and into lane 2 while cars are trying to overtake them safely in lane 2?
the sooner cyclists are held liable for their actions when on the road in the same way all other road usersareshould be the better
I absolutely 100% agree, but so far all you've given is examples of bad driving....
Whether or not you think it appropriate to run TTs or any other event, or even just letting people ride to work on those roads is irrelevant, the fact is it's happening, and so you have to drive safely around them, whether you think they should be there or not.
If the sole basis for banning cyclist on a road is 'because people cant drive safely enough around them' then I think that's a pretty poor argument.