unpleasant to touch
After carefully examining a railing on a very tall bridge in Vevey, Switzerland, we noticed it is covered with a rough material, something of a sand-paper quality. The reason for using this material might be to discourage suicidal attempts, as the contact with the railing is already so unpleasant. On the other side, the reason might be purely hygienic, for it probably gets less dirty when nobody is touching it.