micky wrote:
Brake retarders may not be used in this town, said the sign, just as I
started to go *up* a small hill.

The small town is in a slighty hilly part of Pennsylvania. It's
industrial area is dominated by one company, whose name I can't r ecall
but which might make paper. I'm sure they get qute a few big trucks
coming into town, and they might take this street, for the same reason I
did. (It was the first street that went there, coming from the west.)

What is a brake retarder?

Why don't they want it used? Isn't it good for cars and trucks to
actually stop when the drivers want them to?

That is illegal all over the populated places. Ever drove diesel engine
big trucks? Or used engine brake driving cars with manual shift? Then
you'd know.
It makes loud noise when applied the retarder.