I don't understand the adversion to a bell. True, a single ping of a bell doesn't always work. But sometimes it does. And when it works well, like getting a green light. That's is plus right there.

The pedestrian problem I think needs a context to analyze it. A single pedestrian is more predictible than a group. Multiple groups are even less predictable. On MUPs pedestrians will follow the trail, but on a street corner they can go any direction. This time of year, with the long daylight hours, ninja pedestrains aren't so much as a problem, but they will be back in November.

The "on your left" or a bell won't work at the last second. It just startles people into a reflex reaction, which isn't predictable behavior. Body language is a good indicator, especially noticing what the pedestrian is looking at. It's a clue to what the pedestrain is concentrating on. Tourists are less predictable than regulars. Parents with children are hard to predict. Teenagers are impossible.

The more unpredictable the pedestrian is, the more you are going to have to slow down.