Reading the article on the collapse of unprotected piers of the Queen Isabella Causeway in Texas (NCEI November 2001), I think it would be a good idea to install a monitoring system on such bridges to warn the traffic of a collapsed section ahead.
I mention this after seeing the car in the accompanying picture.
Clearly the driver was unaware of the collapse ahead, as I'm sure many others would be.
A monitoring system could simply be a 'cable' that ran along each side of the deck connected to warning signs at regular intervals that inform the motorists to stop. If the deck collapsed the cable would break and the signs activated, rather like an intruder alarm system.
Jon Sturgess, Monosys, Kuala Lumpur, Malaysia sturgess@monosys. net