RS&H was part of the design-build team that completed the Crosstown Parkway Extension in Port St. Lucie, Florida. The project creates a third crossing into Port St. Lucie, relieves traffic congestion, and provides an additional hurricane evacuation route. The corridor included approximately 1.5 miles of roadway improvements and a 0.75-mile bridge over the North Fork of the St. Lucie River. The bridge traverses a highly environmentally sensitive area, which required minimization of wetland impacts and protection of the Savannas Preserve State Park. This project features unique architecture for the city’s signature bridge, drainage design, utility coordination and design, and extensive landscaping.
A unique feature of this project is the superstreet intersection at Crosstown Parkway and Floresta Drive, the first of its kind in Florida. This innovative intersection is a type of restricted crossing u-turn intersection (defined by the Federal Highway Administration) specifically designed for situations where through traffic on the major road is significantly heavier than the traffic of the cross street. Superstreets have been used successfully in many other states, improving traffic flow and safety. Travelers on Crosstown Parkway treat the intersection the same as any traditional signalized intersection, able to travel through, turn left, or turn right. Those of Floresta Drive are only able to turn right at the intersection. They will then go through signalized, synchronized u-turns in order to travel through the intersection or to turn left.
The intersection eliminates a signal phase, resulting in significant time savings for motorists. Traffic analysis for Crosstown Parkway and Floresta Drive indicated the average delay time was eight times faster and the level of service is improved by three levels both in the opening year (D to A) and design year (F to C) when compared to a traditional four-leg intersection. Safety is also greatly improved by reducing the conflict points from 32 to 14, reducing the frequency and severity of crashes. Pedestrian safety was improved even more than vehicular safety, with conflict points reduced from 24 to eight, and a large median refuge island.