Bridge vs tunnel?

[Amanita]

Here in Halifax, there's been talk of an eventual third harbour bridge. However, they're also talking about the possibility of a tunnel.

You can guess which I prefer- A suspension bridge across the mouth of the Halifax Harbour would be an amazing sight.

But which do you think is generally better? Bridge or Tunnel?

Like I said, I would choose the bridge. Why? For one thing, a good bridge can be a source of civic pride, an icon. Unless it's epic like the Chunnel, tunnels generally don't get such admiration. Lots of people love to drool and fawn over NYC's bridges, but I don't see so much love for the tunnels.
As Robert Moses once said, "Tunnels are vehicular bathrooms."

Also, for the same cost or in some cases less, a suspension bridge can carry more traffic. When studies for the Verrazano narrows bridge were done, they found that a double decked suspension bridge with 10-12 lanes could be built for the same cost as a two lane tunnel.

As far as I know, not only can the bridge carry more traffic, but if need be, its capacity can be expanded if needed. MacDonald Bridge here in town had a third lane added, George Washington Bridge was designed to have a second deck added when needed, and Verrazano was built with two decks from the get-go, with one being opened to traffic right away. The other deck was opened later when demand increased. And let's not forget 25 April Bridge in Lisbon, Portugal. She was designed as a single deck bridge, with the ability to be upgraded later to carry rail traffic if needed. This was eventually done, with other alterations that increased capacity even more.
Even though nothing ever came of it, there have been studies done concerning double-decking the Golden Gate, even.

Screw me if I'm wrong, but wouldn't a tunnel be harder to upgrade so effectively? Unless you wanted to dig a whole new tunnel, that is.