Code of Alabama
Division 3 - Regulations Affecting Public Safety.
Section 37-2-81 - Duty of Locomotive Engineer to Ring Bell or Blow Horn, Etc.

The engineer or other person operating a locomotive on any railroad must blow the horn or whistle or ring the bell:
(1) At least one fourth of a mile before reaching any public road crossing or any regular station or stopping place on such railroad and continue with such signal at short intervals, until such crossing or such station or stopping place has been passed;
(2) Immediately before and at the time of leaving a station or stopping place and also immediately before entering any curve crossed by a public road, not marked in accordance with Section 37-2-80, where he cannot see at least one quarter of a mile ahead, and must approach and pass such unmarked crossing at such speed as to prevent an accident in the event of an obstruction at the crossing; and
(3) At short intervals, on entering into, or while moving within or passing through any village, town or city.
He must also, on perceiving any obstruction on the track, use all means within power, known to skillful engineers, such as applying brakes, in order to stop the train.

Structure Code of Alabama