Published: May 06, 2013 12:50 PM EDT
Updated: May 06, 2013 1:02 PM EDT

SANIBEL, Fla.- An engineering study is confirming that the Sanibel Causeway bridges are safe, despite some small cracks in concrete beams supporting the structures. The firm of CDM Smith says the cracks do bearing close watching.

"I feel the bridges are safe to travel, but some of the cracks are bigger than we would have expected for the age of the causeway.  That is of some concern, and we will certainly watch it, and let you know if anything major changes," says Sanibel Mayor Kevin Ruane.

The engineering study results and pictures of the small cracks are included in the material that the Sanibel Island City Council will see on Tuesday, May 7.

This means two studies over the winter have reached the same conclusions: that the concrete beams are showing cracks because of the type of pre-stressed concrete used in the building of the causeway a few years ago. Lee County's Deptartment of Transportation says the structures are safe, and that inspectors will monitor the cracks very closely in coming months and years.