Can't comment on the sign but it fits the bill (literally)
RAILWAYS CLAUSES CONSOLIDATION ACT 1845
CHAPTER XX.
75. If any person omit to shut and fasten any gate set up at either side of the railway for the accommodation of the owners or occupiers of the adjoining lands as soon as he and the carriage, cattle, or other animals under his care have passed through the same, he shall forfeit for every such offence any sum not exceeding forty shillings.