As David says, I bought as recumbent on medical advice, to reduce the stress on my wrists. It worked extremely well. After 5 years of being unable to cycle on consecutive days due to wrist pain, I found myself able to cycle every day (36 miles a day to be precise).
I really enjoyed the recumbent and I generally felt very safe in traffic. The biggest danger I find is drivers who are on auto-pilot, not really paying attention.
I was hit from behind by a car driver who didn't see me even though it was a bright sunny day and there were no other vehicles in the vicinity.
On a recumbent, you really get noticed, and that's what made me feel safe.
I only went back to the mountain bike last August, again on medical advice, to gently increase the stress on my wrists as part of my rehabilitation after surgery on both wrists. That also worked, but I've had to use ergonomic grips and wrists splints and be very careful not to hit any potholes while leaning on the handlebars - I did get taken by surprise once and it hurt for days.
I was surprised by a couple of things.
1) My legs were significantly stronger - I could ride the mountain bike for longer in higher gears than before.
It's not really that surprising, basically a recumbent is a mobile leg press machine.
Extremely good at working your legs whilst being very easy on your upper body.
2) I actually felt exposed by how high above the ground I was on the mountain bike.
I had got used to being close to the ground in a position where if you do fall, it's only going to be inches.
My conclusion - if you think you might be able to ride a recumbent, you should give it a try. It's fun, safer than people think, and if you have a disability you might find that it transforms your life.
posts
