The abrupt closing of a Pinellas Trail bridge is the subject of this week's Traffic Inbox.

Every day, hundreds of people use the Pinellas Trail, with Dunedin seeing some of the heaviest use.

When the county recently closed the two spans of bridge over Alternate U.S. 19 and Orange Street, it raised a few eyebrows.

"I didn't know was going on," said resident Greg Brosius. "We walk it all the time."

David Deranzio with Pinellas County said it's about erring on the side of safety.

"Once it starts getting to where it's past its life cycle, 25 years, it's hard to keep up on it," Deranzio said. "And that's when we send them out to bid and redo the bridge."

The part in question is the bridge itself. The blue-metal sections are corroded, and in a recent inspection by the Florida Department of Transportation deemed unfit for use.

The county shut them down last week with no notice.

"Just for safety sake," Deranzio said. "We're going to always err on the side of safety. And this is the perfect example of erring on the side of safety."

The issue now is what to do with all those people who use this bridge to cross the road.

Crossing at Orange Street is very dangerous.

"We don't want people crossing Alternate 19," Deranzio said. "We want them to go down to Curlew or up to Tampa Road where there's a crosswalk. It's not safe crossing Alternate 19."

To solve that problem, the county is building a new sidewalk along Orange Street from the trail closure to connect to the existing sidewalk on Alternate U.S. 19.

It will be three to five months once demolition starts before the new span is complete. It will cost $1.5 million dollars.