bridge前可否用定冠词?

有人问到这样一句话:

(1)The Golden Gate Bridge is one of the world's greatest suspension bridges and acclaimed as the world's most beautiful bridge.

但根据《实用英语语法》1995年修订本(张道真编著)第67页最后一行说,Golden Gate Bridge属专有名词前不加冠词,而上述句(1)却用了定冠词the,不知何故?

桥梁,作为专有名词,除去一些比较固定的如London Bridge, Westminster Bridge等一般不用定冠词the外,皆可以用the,亦可不用the。用the的情况除上述句(1)外,再如:

(2)Joseph B. Strauss was the builder of the Golden Gate Bridge . (引自《不列颠百科全书》)

(3)The weather's pretty good, so I'm planning on shooting the Cedar Bridge . (引自《廊桥遗梦》)

不用the的情况有如:

(4)Golden Gate Bridge , suspension bridge spanning the Golden Gate, in California, U.S. (引自《不列颠百科全书》,系简约文体)

(5)Cedar Bridge sat fifty yards upstream from and parallel to the new road and its concrete bridge. (引自《廊桥遗梦》)

那么,上述用the与不用the二者有何不同呢? 从语法上讲,用了the说明该桥梁有区别于其他桥梁的含义;如不用the,那就意味着该桥梁就是一个十足的独立的专有名词了。