The department may require a railroad corporation whose railroad crosses a highway by a crossing above the level of the highway to give such signal as the department may designate of the approach of trains to such crossing. The department may in each case determine the nature of the signal to be given, and, in its discretion, may require an automatic signal.
Mass. Gen. Laws ch. 160, § 149
Signals at crossing of railroad above highway level
Official source: Massachusetts Legislature. Reproduced from public-domain Massachusetts statutes; confirm against the official source for the current text. Not legal advice.