Section 117.478 - Lower Grand River(a) The draw of the LA 75 bridge, mile 38.4 (Alternate Route) at Bayou Sorrel, shall open on signal; except that from about August 15 to about June 5 (the school year), the draw need not be opened from 6 a.m. to 8 a.m. and from 3 p.m. to 4:30 p.m., Monday through Friday except holidays. The draw shall open on signal at any time for an emergency aboard a vessel.(b) The draw of the LA 77 bridge, mile 47.0 (Alternate Route) at Grosse Tete, shall open on signal; except that, from about August 15 to about June 5 (the school year), the draw need not be opened from 6 a.m. to 8 a.m. and from 2:30 p.m. to 4:30 p.m., Monday through Friday except Federal holidays. The draw shall open on signal at any time for an emergency aboard a vessel.(c) The draw of the S997 bridge, mile 41.5 (Landside Route) at Pigeon, shall open on signal; except that, from 10 p.m. to 6 a.m., the draw shall open on signal if at least four hours notice is given. During the advanced notice period, the draw shall open on less than four hours notice for an emergency and shall open on demand should a temporary surge in waterway traffic occur.CGD8-92-16, 57 FR 57962, Dec. 8, 1992, as amended by CGD08-93-024, 59 FR 14756, Mar. 30, 1994; CGD08-96-003, 61 FR 49064, Sept. 18, 1996; USCG-2009-0686, 75 FR 16009, Mar. 31, 2010