I keep seeing these bits of metal on the side of the road/in the gutter and cannot work out what they are or where they come from.

They are clearly made of steel because they are sometimes rusty. It is not hard steel because the strips can be easily bent. They are all the same width (about 2/3 mm) and roughly all the same length (about 20 cm).

Any ideas?

http://i1361.photobucket.com/albums/r674/Clennam/IMG_20150726_1049390561_zpsh3jgqg6a.jpg