117.599—Fort Point Channel.
The draw of the Northern Avenue Bridge, mile 0.1, at Boston, shall operate as follows:
(a)
From May 1 through October 31, the draw shall open on signal from 7 a.m. to 11 p.m. From 11 p.m. to 7 a.m. the draw shall open on signal if at least a two-hour advance notice is given by calling the number posted at the bridge.
(b)
From November 1 through April 30, the draw shall open on signal from 7 a.m. to 3 p.m. From 3 p.m. to 7 a.m. the draw shall open on signal if at least a twenty-four hours advance notice is given by calling the number posted at the bridge.