A horn or bell is mostly for telling other people "hey I'm here, stay out of my way and dont suddenly cross into my path"

My opinion as a cyclist is that I should basically only be using my bell on pedestrians when the pedestrians are wandering onto the bike lane. If im cycling through a shared space, I find it extremely rude to ring the bell, because it feels like I'm telling people to get out of my way, but they have just as much right to a shared path as I do. Some cyclists ring their bells because they're worried a pedestrian might suddenly turn into their path, but I think if one is concerned about that, it's a sign youre cycling too fast, and should just slow down.

With cars, I will sometimes proactively ring my bell at them if I think they're not sufficiently aware enough of me though.

Bicycle bells are mostly for warning pedestrians when approaching from behind and passing on shared-use trails. I ride on shared infrastructure and cannot afford to build new infrastructure when my town will not. Not warning a pedestrian when approaching from behind introduces the possibility of collision if the pedestrian makes a sudden change in his walking course. I typically use this etiquette:

Passing a single pedestrian or runner on a quiet day: no bell, coasting for a short bit with a loud free hub (the rotating ratchet element on the rear wheel) alerts the pedestrian to my presence.

Passing a runner: normal ring from a distance so they have knowledge that the bicycle is passing

Passing a cyclist: one loud ring from a distance

Passing a pedestrian walking a dog: two loud rings, one far, one close, so that the pedestrian is aware of the approaching bicycle and he can prevent his dog from running at me/colliding. Many dogs do seem to enjoy a bicycle chase.

Antisocial pedestrians (i.e., walking side-by-side such as to be blocking the path in both directions, preventing the bicyclist from passing): several loud rings of the bell until the antisocial activity has abated. Announcements in my local tongue (not English) that they impede the flow of traffic.

It's not only about preventing accidents (but I do believe it prevents some to attempt answering your question).

It's also about signaling to someone that they might be doing something wrong or they might not be paying attention. For pedestrians it takes significantly less time and distance to stop, for cars, trams, and bicycles, it takes longer.

It happens all the time that pedestrians don't know the customs of a country, they don't recognize bike lines... in that case the cyclists do not need to pump the breaks anytime a clueless tourist gets in front of them... they can ring the bell, signaling:

"yo, it's not how we do it here, please watch out, I'm coming full speed and you are in the wrong, so please look up from your phone and stop right there".

I also had the luck to meet some people thinking they can be on their phone while cycling, drifting into my lane, etc... In that case, a bell is also adequate

"hey, please stop writing a text message while you are on your bike blazing through the city, you are driving as if you were drunk, pay attention please and stop multitasking (you moron)"

If nothing works to change their behavior, of course I'll try my best and hit the brakes safely, but I'd prefer they learned how to move around in the city safely.

"Do horns and bells really prevent accidents?"

If you are a sane person, absolutely not!! You _try_ the bell, if people react, then you go. Many times it just confuses people or people ignore it.

If you are a high-speed maniac and _rely_ on the bell to clear a path for you... then yeah. But you are then also likely to take great risks in general and will probably be in other accidents...

I've been a cyclist in SF and in Amsterdam, both for many years.

In SF I used my bell much more aggressively. It was mainly for cars, if I'm in or entering their blind spot and my spidey sense tells me they are considering an action that places me in danger. For example, we all know when driving when the car in front of us is thinking about merging, even before they indicate (often I feel like I know before they do). I also used it for pedestrians stepping out into the street who are maybe looking past me for oncoming cars but somehow don't see me, or when approaching 'blind' situations like a sharp corner, a driver pulling out of a driveway but there is a tree between us, delivery drivers stepping out from their truck, etc. I can't say how many accidents have been prevented (the person may have eventually looked and seen me), but I can say that my bell has triggered people to look and see me earlier than they were going to had I not rang it.

In Amsterdam my bell is used much more sparingly. It's mostly for tourists stepping into (or considering stepping into) the bike lane. If they are already in the bike lane, I almost always prefer just to slow down a bit and dodge them, as ringing the bell often triggers a deer-caught-in-headlight moment or erratic behavior, which increases the chance of an accident or that I have to come to a full stop. The other situation is to express dissatisfaction at cars blocking bike lanes, cars/bikes not yielding, drivers blocking intersections, or other dangerous behavior. This isn't preventing an accident but I'd argue it is still important, as social control affects how often we make bad decisions. Outside the city I also use my bell to let other cyclists know I'm passing.

So yeah, I'd say bells prevent accidents, but obviously not as well as good biking infrastructure, where pedestrians, bikes, and cars have clear separate spaces, and visibility of cyclists to drivers is high.

> In order for e.g. a horn to work you need enough time that the driver processes the situation and decides the horn will communicate something AND enough time for the pedestrian or whatever to process that and react to it. Generally it's a lot easier just to press the brake, and more importantly be travelling at a speed and in a manner where the brake is sufficient

I have seen a small kid jump from his father's scooter just when I was overtaking them and they decided to stop because he had seen his grandpa or whoever was that old guy on the other side of the bike lane. His father managed to stop him by grabbing his sweater because I had rung my bell a few seconds before he decided to stop but the kid ended up inches from my bicycle. It was at very low speed, almost walking speed yet hitting a bicycle handlebars head first because you turn around without looking still hurts even if the bicycle his stopped.

horns & bells are for pedestrians IME, not cars.

>> properly segregated infrastructure for each class of vehicle.

I ride a lot in traffic and the problem with segregated infrastructure (i.e. bike lanes) is the interfaces and constriction. Pedestrians step off the sidewalk or out of cars into constrained bike lanes all the time and there's no where to go; cars turn across bike lanes with the same problem.

You can't always do it, but if you can eliminate the speed differential I believe riding in traffic is much safer than a bike lane, at least until you get enough bike volume to keep drivers aware. THat's hard to do in most of NA or year round.

> Do horns and bells really prevent accidents?

They absolutely do, for indirect reasons:

> Generally it's a lot easier just to press the brake

Maybe easier, but it hardly seems fair, nor realistic.

With a bit of experience, you can tell when pedestrians are likely to stumble onto the bike lane without looking. Then you have two choices: Significantly reduce your speed, or ring your bell first and only reduce speed if they still haven't noticed the oncoming bike.

If you only reduce speed, you'll be traveling at a very low average speed, and time is money (especially for bike delivery workers, but I also hate having to sharply decelerate for people glued to their screen or otherwise completely unaware of their surroundings even if I'm not in a rush), so you can take a guess as to whether "just reducing your speed" is practicable.

A car company wanting to divert attention away from the carnage cars cause. Seems a bit suspicious no?

Bells don’t work on cars, I’ve been using this in SF and motorists respond very quickly

https://loudbicycle.com/

You're right, it's certainly not the primary way to prevent accidents. But it helps at the edges, which seems worthwhile.

That's assuming the bells aren't abused too badly, which is a mixed bag, but mostly true.

There are a lot of runners on mixed use paths wearing headphones these days. They are an absolute danger to overtaking bikes. A bell they would hear would be useful.

They certainly can, yes. Many crashes can be avoided if both parties slam on the brakes or swerve, not not quite if only one does. Also they're useful in parking lots when some dumbass is about to back right into you.

I concur. Even the best bell in the world may be utterly useless if the pedestrian happens to be deaf. Also, bicycle bells tend to polarise pedestrians - some people think that bells are rude and insisting that peds get out of the way and other people think it's dangerous and rude to not use a bell every time you overtake.

My solution is to still have a tiny bell on my road bike, but instead of using it, call out something like "can I get past, please?" or if an immediate response is required (e.g. ped blindly stepping into the road ahead of me) then yelling "Oi!" can really surprise them and make them notice you. I'm also a fan of using "Beep, beep" if a ped is on cycle infrastructure (active travel infrastructure is probably a better term) and I want to pretend that I'm an impatient driver.

I think the human voice is far superior to a bell as you can tailor the message for the situation and you don't have to move a hand away from the brakes to do so. (Using your voice is also a very good idea when approaching a horse and rider - horses know about humans and don't get freaked out if you call ahead "Morning!" or something cheery and appropriate).

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