On 09/08/18 17:49, JNugent wrote:
On 08/08/2018 19:20, TMS320 wrote:

On 08/08/18 16:28, JNugent wrote:
On 08/08/2018 15:24, TMS320 wrote:
On 07/08/18 15:27, JNugent wrote:


The obvious use whilst moving would be when approaching ths "summit"
of a hump-backed bridge or a sharp bend.

Perhaps you mean something like this? It is is harder seen from a
driver's perspective than from a high mounted camera. No need. Adjust
speed according to what can be seen.

https://goo.gl/maps/9MSMX69BxzM2

Not hump-backed enough to need it. You can easily see traffic
approaching from the opposite direction, even if driving a Triumph
Spitfire.

I know a Spitfire owner so I shall have to ask. When looking around
Streetview various perspectives show they put the camera roughly level
with the height a high roof Sprinter van (2.8m). Believe me, it is
difficult on a live approach where you also don't have the luxury of
spending time looking at a static scene.

In order for the horn-sounding to be even semi-valid, the bridge really
needs to be a narrowing of the road as well (which the Italian one was).

https://goo.gl/maps/R48YMSxzjQk

That one...

....is the same one from other direction.

is narrow, but you can still see the oncoming traffic. Sounding
the horn would not serve a useful purpose.

Incidentally, the bridge has a 2t mgw limit so several drivers shown
here are breaking the rules - plus many others plus a council official
with a Range Rover that knows full well.

There's no sign saying so. Is this an older Google photo?

The signs are at the roundabouts at each end of the road.

A multi-storey car-park near here had a down-ramp with a give way
line at the bottom of it, with the posibility of traffic approaching
from the left. A sign on the wall said "Sound Horn". I never did.

Weird.

Exactly. I bet someone thought it was clever, though.

There were houses near the location and the occupants were as
entitled to reasonable efforts to keep down noise as anyone else is.

Well done you.

Likewise, an Italian friend used to sound his car horn on a
hump-backed bridge near his village. But the bridge had a house
adjacent to it. He would never listen to my remonstrations; I gained
the impression that he...

[...revelled in it.]

Sorry, missed that out last time.

OK

If the horn was not so unpleasant, the administrators that defined the
90dbA standard understood physics and the pad on the steering wheel
was force sensing to allow the driver to add expression it might be
more acceptable.

Is that the C&U standard? I never knew that.

Yes, 90dbA at 2m is the standard. The problem is that it isn't sensible
to measure a narrowband signal with a wideband instrument. A wideband
90dbA source would be completely inaudible inside a vehicle.

In case your thoughts are drifting, the "150db" horns used by some
cyclists are probably fairly similar, except measured in a different
way. If it was done in the same way, the extra 60db would require a
million times more power.