Suddenly around town I’ve noticed that loud speakers have begun appearing between the traffic lights at intersections. Anybody know why they’re there? They’re certainly not cameras, as cameras sit above the lines, and these are slung below them.
I’ve seen a few in the LA area that would sound an audible beep when pedestrians had a ‘walk’ signal in one direction. Presumably to make it easier for blind pedestrians to know when it’s safe to cross?
Correct. It is an aid for blind people. Different speakers will emit different tones so the blind person will know which way to face.
The speakers are to assist the visually impaired.
They come into two types:
- ones that beep one way for people crossing E-W and a different beep for N-S
- ones that just have a voice that say “Cross X Street” or “Cross Y Street”
Heh.
Reminds me of a joke/anecdote.
An American tourist in London is sitting in an open top bus. The bus stops at a pedestrian crossing, and there is a loud beeping noise.
The tourist, perplexed, asks the tour guide what the beeping is for. The tour smiles and says “It’s to tell the blind that the lights have changed to red.”
The tourist looks shocked and says “I’ll be darned! You see, in America, we just don’t let the blind drive!”
made me laugh anyway 
.
Okay, if they’re for blind people, then why am I seeing them only at intersections which don’t have crosswalks?
They have those at Michigan State University. They used both the announcement and the beeps. They get on your nerves after a while.
They have those at the main intersection in the town where I work, Indiana PA.
It emits an annoying bird tweeting noise.
As Diceman said for MSU, I was on campus at Georgia State University, and the streets there had the beeping speakers. It was the only time I encountered this system. Trying to answer the question myself, I saw mechanics at the intersections in their pick-ups. To be honest, the entire concept of the blind using the system never entered my mind.
I (falsely, obviously) concluded that the beeping was to the traffic light itself, not the concept to cross. (I heard that Atlanta was finaly going to syncronize the traffic lights, and GSU is in the middle of downtown, I thought the speakers would somehow assist the mechanics in figuring out the timing of lights.)Oh yeah, I haven’t heard any beeping from the units, either. (No radio in the car, and the windows don’t go all the way up, so if they were beeping, I’d hear 'em.)
I’m amazed that there’s anywhere that hasn’t made provision for blind people on crossings - in the UK, every crossing has either beeps, or a button on the bottom of the control-panel-thing that spins when it’s OK to cross, or both.
Related question: Why do some red lights also have a flashing white strobe light? Sometimes it’s a horizontal line in the center of the red, sometimes it’s a separate small light on top of the whole fixture.
If you haven’t heard them make any noise, what makes you think they are loud speakers? They may be directional microphones for emergency vehicle sirens.
There’s one on the light in front of my office. It’s in the middle of a street for pedestrian crossing, no intersection, and it’s pretty easy to miss if you aren’t paying attention. I assume the strobe is there to get driver’s attention in a place where they might not expect a light.
Having some experience in audio engineering, I can say that I’ve never seen any kind of microphone which looks like that, directional or not. They do, however, look like bullhorn speakers. Also, I would think that if they were for the purpose you propose, I’d see a lot more of them, instead, it’s just a few here and there.
The only ones I have ever heard talk instead of beep, in the most annoying, monotone female voice ever.
I forget what it says, but it has to be something like ‘It is safe to cross’.