I've noticed the fact that the handrails and the steps on an escalator are not synchronized and always thought that it must be a safety feature that keeps people leaning slightly forward so that they do not tumble backwards as they daydream. Of course this would only be true - and would only be a safety feature and not a hazard - if it only occurred on ascending escalators. I haven't noticed if it does occur on descending escalators, but will pay attention on my next trip down.

I have no idea how escalators are actually built mechanically, but if you think of the escalator and handrail running in loops it's possible the handrail and steps run at the same rotational speed, but because the handrail has a longer loop (because it's higher than the steps) it moves faster along it's path.