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Lisbon also has a bridge that you can hear from miles away: one lane in each direction has a surface made of metal grating which makes a loud hum when cars drive over it.

People who live nearby don't notice it (strange looks if you point it out) but I think it's sad that it's impossible to escape the constant noise in certain places.

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Were just there last fall, and yeah, it's incredibly loud, both going over the bridge, and from the viewpoint, and.. well, pretty much all over I imagine. I will say, I didn't notice it from the city side, though -- perhaps because of the way the city curves away from the bridge, or because you're "underneath" the sound rather than above it.

Another relevant bit about Lisbon's 25 de Abril bridge is the common misconception that it was designed by the same company as the golden gate, as it looks similar and also has a red paintjob, when it was in fact the company that designed the Bay Bridge, which is even more similar (except for the colour).

I guess there aren't all that many companies that can build such massive bridges. Now I'm wondering where else I might have seen a bridge made by the same people.

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