Due to recent events, I finally feel like maybe it's safe to ask this question here. First, a little background:
A friend at work and I commute to and from work by bike. Most of the trip is on low-speed rural roads with hardly any traffic. But there's a mile-and-a-half section that's on a narrow, 55mph road that is usually pretty lightly trafficked, but occasionally we'll end up with a car (or large truck) approaching from the front and one approaching from behind, and there's no shoulder outside the white line. On our road bikes, we don't worry much about that situation. There probably isn't technically enough room for them to stay in the lane and keep three feet from us, but they do it anyway, and I'm used to it. (Sometimes they'll actually crowd the oncoming car instead. Often, the car behind just slows down until the oncoming car passes.)
I have a recumbent trike, which I'm almost finished building a velomobile-style shell for. My friend is planning to get a trike and build one soon. When I first started riding the trike, I had the three-across scenario occur with a semi coming up behind me. I could see it in the mirror well in advance, so I decided to pull off the shoulder. It was an inconvenience to me, and I got weeds stuck in the idler, so I decided to just hold my lane and count on the vehicle behind me to slow down and wait. That's what I've done since, and it hasn't been a problem.
Because the trike is a little wider and can't ride halfway off the road like a bike, there really isn't room for cars to squeeze past. My friend is worried about riding on that road and taking the lane. My thinking is that I'll take the lane and keep an eye on the mirror. If it appears that the vehicle is going to run me over, then I'll bail off the road. He thinks we ought to slow down and pull over.
Bailing off the road at speed could be dangerous because of the steep shoulder. Also, I might wait too long and end up getting hit. But the chances of getting hit from behind when riding such a noticeable vehicle seem miniscule.