I pulled both of my children in a trailer pulled by my road bike (with a skewer hitch). Currently, my younger child rides a trail-bike -- I'll pull the trail bike (she doesn't pedal much) AND the trailer using my triple-equipped road bike. I'm in Colorado and some of the uphills take effort, but it's certainly doable.

Redrom, consider this commentary about the level of perceived "control" of a situation and the amount of risk people are willing to accept. The less control you have, the less risk many people are willing to accept, although statistically the real risk is equal or less than that of many other everyday activities.

Example: Some people are terrified of flying, and a significant population feel some anxiety in the plane because they are not in the driver's seat, so to speak. This is not a rational fear, but people feel the fear anyway.