Part of my commute is a canal tow path, I've had several instances where I've rung my bell/shouted "bike!" when approaching a pair of walkers and the walker on the left goes to the right and the walker on the right goes to the left! One pair even managed to head butt each other! At least it's now light for the commute home so I can see those wandering along an unlit path wearing black clothes.

Generally, unless you have clear line of sight and plenty of room it's slow down to the speed of the slowest. You still get a minority who moan that "You should have rung your bell!" (I've been doing that for a minute you *****!) or whatever.