The draw of the Carlton Bridge, mile 14.0, between Bath and Woolwich shall operate as follows:

(a) From May 15 through September 30 the draw shall open on signal; except that, from 5 p.m. to 8 a.m., the draw shall open on signal if a two-hour notice is given by calling the number posted at the bridge.

(b) From October 1 through May14 the draw shall open on signal; except that, from 5 p.m. to 8 a.m., the draw shall open on signal after a twenty-four hours notice is given from 8 a.m. to 5 p.m., on Saturday and Sunday, after an eight-hour notice is given by calling the number posted at the bridge.