Today, I rode a tricycle. In a way, this is almost a follow-up to my memories of bicycles past, because I have not been on such a vehicle since I was very much smaller. I did ride an electrified trike at an electric vehicle meetup about 10 years ago, but it was a recumbent model with two wheels up front. Today, though, our library received a cargo trike similar to the one pictured below for outreach activities and deliveries.
Our Youth Services librarian, Miss M, had planned to store it in our library meeting room since it has become an interim storage space during the COVID-19 social distancing policy that ended all meeting room activities and required removal of many chairs from the main library. However, our door is about an inch too narrow to wheel the trike through. So instead, I rode it to her home while she led the way through town in her vehicle. It wasn't a long ride, but it required a serious effort to ride well.
You might think three wheels means more stability than two. This is only partly true. You can lean into corners on a bicycle, and this improves handling. The trike does not lean. The steering geometry and inertial forces feel very, very wrong at first. I was told a youth librarian from another branch couldn't cope with the weirdness, and that response bizarrely makes sense. It has all the controls of the bicycles we have all ridden for years, but it does not handle like a bike and it consequently messes with your head.
I don't think it's inherently dangerous, but I suggest people try one in adulthood just for the strange sensation. And if you need a human-powered cargo hauler, try out other models to see what you like before you spend any money. The current interest in greener off-grid living has also made longtails, long johns, tadpoles, and more into something we may see more often over time, so find out what your local bicycle dealer has on hand if that interests you, too.