PROBLEM/SITUATION: Florida's State Road 60 was a dangerous, narrow stretch of road motorists would go out of their way to avoid. Yet expansion was limited because it passed through environmentally sensitive areas.
SOLUTION: Use of GIS
software provided an easier, faster process for designing alternate routes while
ensuring sensitive areas remained protected.
JURISDICTION: Florida Department of Transportation.
VENDORS: Greenhorne & O'Mara Inc., Intergraph Corp., Bentley Systems Inc., HMR Inc., Hewlett-Packard.
CONTACTS: Eddie Yue,
consultant manager, Florida DOT, District IV
State Road 60 across rural central Florida's Indian River County is a 25-mile corridor through sub-tropical swampland, endangered-species habitats, sensitive wetlands, citrus orchards and cattle ranches. Exotic and diverse as the area may be, the narrow, two-lane road through it is a dicey affair with narrow shoulders, ditches on either side, and heavy traffic from agricultural trucks. It has a high incidence of traffic fatalities, and although east-west corridors in Florida are few, even locals go out of their way to avoid this one.
According to Edward Yue, Florida Department of Transportation's (FDOT) project manager for District IV, "Indian River County surveys indicate that nearly 80 percent of the residents are afraid to travel SR 60 west of I-95. In 1991, 15,000 county residents signed a petition favoring improvement, one of the largest petitions for road improvement in recent state history."
Now, SR 60 is about to change. Recently designated by FDOT as a main artery in the Intrastate Highway System, it is to be expanded to four lanes with a center divider. Yue stated that, in addition to being safer and less vulnerable to flooding, an improved SR 60 will promote greater sharing of resources between Florida's two coasts. It will also serve as an effective east-west evacuation route in times of disastrous hurricanes.
Before actual construction begins on SR 60, however, the Project Development and Environment (PD&E) Study, now 70 percent complete, must go through public hearings and be approved by various state and federal agencies. Given the sensitive nature of the area, FDOT guidelines for the project required extensive environmental and social impact studies; engineering designs for three 25-mile alignment alternates, impact assessments for each; and a proposal for a preferred, fourth alternate comprising the best characteristics of the three. Deliverables are to include finished drawings in digital and hard-copy formats of each 25-mile alignment, scaled to 1 inch =100 feet.
The consultant for the project is Greenhorne & O'Mara, headquartered in Greenbelt, Md. According to Tony Drescher, project manager of G&O's West Palm Beach office, the firm would not have taken on a project with this length of roadway had it not already developed a rapid, much-simplified design process exploiting leading-edge GIS technologies. G&O first used the process in the recently completed PD&E study for the expansion of a five-mile section of Miami Garden Drive, in North Miami, from four lanes to six. "In comparison to earlier methods," Drescher said, "the new process cut project time by a very conservative 40 percent."
THE DESIGN PROCESS
At the core of the process are Microstation and Descartes, the only software systems used. Microstation is a CAD graphics driver for various GIS applications, and can operate throughout a local-area or wide-area network. Descartes is a high-speed GIS software capable of digitally linking hundreds of separate raster (electronic) images into a single file. SR 60 project personnel can pan across a "seamless" map of the entire 25-mile corridor; pull up any section and make changes; create layers of different attributes; manipulate color schemes; change scales, and to a limited extent, alter the raster image itself.
An important feature of Descartes, explained G&O Senior CAD Technician Lanny Brady, allows users to selectively superimpose transparent layers of spatial data over the raster image of the aerial. Engineers plotting alignments on the design layer can see wetland delineations