My own bent riding experience has borne true CMs observation. Surely more space by motorists contributes to safety! It also has the added positive side effect of relaxing me, and being relaxed helps lots in not making stupid decisions.

A second safety consideration was speed. Bents are faster. The faster you go the closer you are to matching vehicle speeds. When the speeds are more evenly matched you have more time to make decisions. You also feel more comfortable taking the lane. Also again, more relaxed!

The seated front facing posture is great for taking in the environment. Another plus for safety.

Breaking hard on the front wheel (the more effective wheel for slowing down) is less likely to result in me getting thrown over the handlebars because the handlebars are literally in the way (unless you've got USS).

That's just from the top of my head. I'm sure there are more.