Replacement PD&E Study/Design, Treasure Island, Pinellas County, Florida: E.C. Driver is the prime consultant for an ongoing PD&E study for the replacement of two fixed bridges and one bascule bridge located along the Treasure Island Causeway. The three bridges connect the City of St. Petersburg on the mainland to the City of Treasure Island. The existing bridges are considered both structurally deficient and functionally obsolete.  The bascule bridge crosses the Intracoastal Waterway and provides only 6 feet of vertical and 85 feet of horizontal clearance. 

The PD&E Study was conducted in two Phases. In Phase I the federal study limits and a wide range of possible solutions were investigated including alternate alignments, various bridge types, a tunnel, and possible rehabilitation.  Phase II of the study included detailed analysis of potential engineering, environmental and social economic issues and detailed development of viable alternatives. Key evaluation factors included avoidance of publicly owned parks and adjacent historical sites, visual impacts to adjacent residents, impacts to local access, potential relocation of the toll facility and avoidance of seagrasses.

A vessel height survey was conducted to determine the most appropriate alternatives.  A bascule bridge with 21 feet of vertical clearance bridge was selected as the Preferred Alternative.  Design of the replacement fixed bridges is complete and design of the replacement bascule bridge is currently underway.  As part of the PD&E Study  an extensive public involvement plan was implemented including a project web site, newsletters, small group and large-scale public meetings and presentations to the City Commission.

As a result of the PD&E Study  the three bridges were determined to be eligible for listing in the National Register of Historic Places.

Client: City of Treasure Island

Study Completion Date: April 2003