I guess you have never been there to say that - the whole bridge crosses a 8+8 lane highway (Marginal Pinheiros) and a 4+4 lane Avenue (Berrini). It was built to give another option to cars to get to the main highway (Imigrantes) to the seashore of the state, as today access to this highway is extremely crowded by trucks.
I tend to agree with rafaelfri - Whilst the bridge is a beautiful engineering feat, was it neccessary? The alignment seems to be forced rather than required. This is where a fine line is drawn between form and function. Some structures around the world have function that take priority, form is then achieved by coincidence or just pure luck. This has neither, unless someone can expalin why the alignment is the way it us.