These are not subjects anyone will reseach and publish papers on.
The topics will not get much recognition!
Normally legs (and other members as well!) of transmission towers
would be galvanised. If the location is close to sea, (coastal
region) they can be painted. That will give a better appearance,
in addition to corrosion protection.
Lamp post, being in places where there is constant presence of
people, should be painted for good appearance. This will
automatically protect the post from corrosion.