Leo Lichtman wrote:

"Trevor Jones" wrote: (clip) If you are at all concerned about liability
issues from it being hit, plant a really good solid base into the ground and
mount the post onto the base at ground level with fairly light duty bolts so
it can shear off, but be reinstalled easilly.
^^^^^^^^^^^^^^^^^
How about incorporating a coil spring (like from a car front suspension) at
the foot of the post, so instead of bending or breaking, the post springs
back?

Imagine that being hit by a car and tell me if you think it will ever
stand up straight again.

I think it better to break clean than to hang on and get mangled.

Cheers
Trevor Jones