On a matter of cycling practice in difficult circumstances.
Here's one. Driving on the right (USA) It can be difficult at times to judge the correct time to move left in order to execute a left turn. This is especially true if there are 1 or more lanes to cross and traffic moving at differing speeds. (The same is true for right turns in the UK etc.)
There are a couple of places on routes that I ride where this is the case. Occasionally there will be a situation where a platoon of traffic is approaching, such that it would preclude safe & easy manouvres at the usual distance from the intersection. In this case one can choose to move early, whilst you have the road to yourself. This brings the problem of riding in the leftmost lane with traffic for some distance before the left turn lane is reached. I have a tendancy to bias left in this situation, such that cars pass to my right, but there is the option of full lane occupancy. This latter choice might be vehicular, but it certainly feels exposed. Occasionally there is a honk on the horn from a motorist .
Then there is the need to move through steady traffic that is moving faster than the cyclist e.g. a 2 or 3lane (each direction) expressway with 45 mph limit. Cars often let you in, but there is no guarantee, and it can be hard to trust that each has acknowledged you as you shift lanes.
I'm not a shy cyclist, but these situations can still put the wind up me on ocasion.