[RamiK]

More so considering the city might want to close down the bridge (eh... open it? lift it?!) remotely in case of an emergency. They might also want to throw in some traffic condensation sensors and cameras for security and/or tickets and so on...

[userbinator]

It wouldn't surprise me if the new system turns out to be less reliable and not last as long, due to all these added things. This isn't aerospace-level, but it's still an application where bugs can be truly dangerous (e.g. bridge attempts to open while you're driving across?)

http://en.wikipedia.org/wiki/Second-system_effect

[koenigdavidmj]

We actually have relevant history of that in Seattle. The 520 bridge opened whilst traffic was running back in the 80s, killing one.