OAKLAND, Calif. -- The collapse of that Bay Bridge eyebar last autumn shook up not just the bridge but many drivers who lost faith in the span's integrity. But now there may be a high-tech way to detect when a bridge part or the bridge itself is weakened.

In the earthquake-prone Bay Area, the daily drive across a bridge can be a leap of faith. And it's not just earthquakes that worry some drivers.

Some saw their faith shaken when 5,000 pounds of steel rained down on the top deck of the Bay Bridge in high winds last October.

"All of a sudden, the cable fell in front of me and I had no idea what it was," said Andrea Nelson. While Nelson was uninjured when the eyebar repair failed, the debris seriously damaged her car and two other vehicles.

"It was very scary and I thought I was going to go into the bay because I drove over it and my car swerved," said Andrea Nelson.

The eyebar failure stirred memories of the 1989 Loma Prieta earthquake which collapsed a 50-foot section of the Bay Bridge.

"It's very difficult to put an exact number on how many of our bridges are fatigue sensitive," said University of Michigan Professor Jerome Lynch

University of Michigan engineer Jerome Lynch heads up a national project to make bridges "smart" by using high-tech sensors to alert engineers when sections are fatigued and close to failure. Fatigue can be caused by high winds or by overloading a span, such as when the I-35 Bridge in Minneapolis collapsed in 2007, killing 13 people.

"We may underestimate the amount of fatigue structural elements a bridge might see," said Professor Lynch.

The project is funded in part by a $9 million federal grant. It includes applications such as a so-called "sensing skin."

"For example, we can actually place this on a structure of a bridge deck and measure the amount of corrosion of the interior of a bridge deck just by wirelessly reading this from afar," explained Lynch.

The immediate goal is to deploy cheap, wireless sensors on every major U.S. bridge. These sensors can make complex measurements without hundreds of yards of cable. Some are even powered by vibration.

"It’s a very low-cost prototype costing about a $100 per sensing node. You can see it has an antenna for its wireless sensing capabilities," said Lynch.

Last November, University of Michigan engineers partnered with Caltrans and a South Bay company to test about a dozen wireless sensors on the Carquinez Bridge.

It quickly became a case of too much information because the sensors generated gigabytes and gigabytes of data.

"The problem with doing sensors is not only getting the data out, it's making sense out of it," said Alex Krimotat, a vice president at Sunnyvale-based engineering company S.C. Solutions.

Engineers at the company are using mathematical models to organize that data and determine where to place sensors.

"The bridge deck is a good example of where it gets complicated because it's a continuous. It's like a kilometer long, so there are almost an infinite number of places where you could put a sensor," said S.C. Solutions' principle research engineer Gwen Van Der Linden.

The idea is to make it simple for bridge operators to understand precisely where and what the problem is.

"If the maintenance department has a screen that says 'green light' or 'yellow light' or 'red light,' that's all they really want know. and if there's a yellow light, go look over there," said Krimotat.

Caltrans officials said there are already more than 100 motion sensors on the Bay Bridge and dozens more on the Carquinez Bridge that measure movement created by an earthquake.

Officials said the next generation of fatigue-measuring sensors may offer a better understanding of bridge stress before and during an incident.

"When you have good, hard data on what any bridge is going through during an earthquake or even during high winds, that knowledge is golden," said Caltrans spokesman Bob Haus.

Engineers developing the new sensors said they will be invisible to motorists.

"As far as the travelling public, they can be a lot more confident crossing these bridges that things are being monitored as they go along, as they drive on it," said S.C. Solutions’ Krimotat.

Andrea Nelson said she welcomes the new technology, but last October's incident has made her cautious about trusting the Bay Bridge again.

"It's very recent, so I don't want to cross that bridge," said Nelson.