There's another reason... reassuring passengers every time they pass by
it that pilots are going to obey the noise abatement rules. I've had
pax point out the signs at my local airport and after telling them what
it's for they usually nod approvingly.

--
Guy

wrote:
In the summer taking off from LAX for JFK a sign at the end of the
runway or thereabouts read no turns until over the water. Why is this
sign necessary for pilots? Don't they know that already?
An interested passenger