DAVIE, Fla. -

The Town of Davie prides itself on its rustic architecture and design, but rusty may be a better way to describe this bridge on Orange Drive.

SPECIAL SECTION: Bridges on the Brink

It's roughly 40 feet long and the lifespan of this crossing over the N-17 drainage canal is getting short

We waded into the water to see why the state Department of Transportation says this bridge is structurally deficient.

Underneath, it resembles an abandoned gold mine. Cobwebs cover the aging steel girders, which are stained desert orange from the all the rust. In some places the corrosion has eaten right though the beams.

It took 40 years, but it appears South Florida's salty environment has finally double-crossed this connector. And all of this decay is playing out under a stampede of traffic overhead. More than 12,000 cars a day travel this two-lane road through a one horse town.

The Town of Davie didn't respond to our questions about what they plan to do with their broken bridge, but city officials have spoken to the state, which passed along their plan to us. The plan says they are going to begin demolition and construction in January of 2013. They're about four months late.

"We kind of know our bridges like our children," said Florida Dept. of Transportation Maintenance Engineer John Danielsen. "We would not let cars go over an unsafe bridge."

Danielsen says state inspectors are keeping a close an eye on all 15 bridges labeled structurally deficient in Broward, especially one of the busiest -- Broward Boulevard over the North Fork of the New River. It's just east of I-95 and handles both ends of rush hour traffic in Fort Lauderdale.

The pilings don't look so bad. That's because they have been wrapped in a fresh layer of concrete. Inside, it's a different story.

Danielsen showed us what 40 years hovered over the brackish water has done to the material by breaking off a piece with his bare hands.

"Over time, the chloride gets into the piles and deteriorates them," he said.

This bridge is scheduled to be replaced at a cost of about $7 million, but not for another three years.

More than 37,000 vehicles use the bridge every day. At that rate, state inspectors are counting on these decaying supports to carry the weight of 41 million more cars.

"If we have any concerns with it, we will close it or we will post it with a lower weight limit. For now, it's a pretty good bridge," Danielsen said.