TRANSPORTATION

The purpose of this Systems Interchange Modification Report (SIMR) is to seek engineering and operational acceptability of the modifications proposed to interstate system access along Interstate 95 (I-95) at State Route (SR) 804/Boynton Beach Boulevard and SR 9/I-95 at Gateway Boulevard in Palm Beach County, Florida. The SR 9/I-95 corridor is a significant component of the Strategic Intermodal System (SIS) and provides a key transportation element in linking the major ports, airports, and railways that handle Florida’s passenger and freight traffic.

Demand exceeds capacity on this segment of road, resulting in peak hour congestion and speeds well below the posted speed limits. This condition is expected to worsen in the future as the population of the State of Florida, including the Boynton Beach area, continues to grow. The volume-to-capacity (V/C) ratio for this segment of SR 9/I-95, its corresponding ramps, and arterial roadway networks will be significantly greater than 1.0 in the future, resulting in deteriorated operations and safety along the corridor unless capacity improvements are provided.

A Methodology Letter of Understanding (MLOU) was approved by the Florida Department of Transportation (FDOT) District 4 Interchange Review Committee (DIRC) and the FDOT Central Office in November 2015. Traffic forecasting and traffic operational and safety analyses for this project were performed in accordance with the guidelines established in the MLOU.

Several alternatives were evaluated to address the purpose and needs identified for this project. These include the No-Build Alternative, Transportation Systems Management and Operations (TSM&O) Alternative, and six Build Alternatives (three at each interchange location). The Build Alternatives proposed for this project include similar improvements to accommodate future traffic patterns. The first Build Alternative for either interchange implemented the improvements suggested in the SR 9/I-95 Interchange Master Plan (IMP) referred as the Concept Design Alternatives (CDA).

Rear-end crashes are the most predominant crash type within the region and are indicative of congested roadway conditions. The Build Alternatives show improved traffic operations and safety within the project study area when compared to the No-Build Alternative.

The three Build Alternatives at each interchange were compared with each other with respect to traffic operations and safety. The detailed comparison of traffic operations with the three Build Alternatives along with the No-Build and TSM&O Alternatives is presented in Section 6. Safety evaluation of the Build Alternatives is presented in Section 7.

Based on the evaluations of the No-Build and Build Alternatives, and in coordination with the FDOT District 4, the District Interchange Review Committee, affected stakeholders, and public comments, the below Build Alternatives are recommended as the Preferred Alternatives for approval in this study:

- The recommended Preferred Alternative for SR 804/Boynton Beach Boulevard interchange is Build Alternative 2 – Streamlined CDA.
- The recommended Preferred Alternative for Gateway Boulevard interchange is Build Alternative 3- Single- Point Urban Interchange (SPUI).

Both Preferred Alternatives will incorporate viable TSM&O improvements and will be developed further as the PD&E project progresses.