Apples to appleseeds. The main span doesn't cross the entire gap. The main span is just the middle part, typically a small fraction of the overall length between endpoints or shorelines, however those are defined.
Well, in this case, the main span will cross the entire gap (or at least it's planned to do it). This BBC article has a rendering which is higher resolution than the one in the Wikipedia article: https://www.bbc.com/news/articles/c80d74v0e4lo
