The Florida Department of Transportation (FDOT) District Five has prepared an Interchange Operational Analysis Report (IOAR) for the proposed realignment, signalization, and widening of the eastbound I-4 to eastbound Saxon Boulevard off-ramp at the I-4 and Saxon Boulevard interchange located in Volusia County, Florida. The proposed improvement will also extend the third eastbound through lane on Saxon Boulevard through the I-4 Eastbound On-Ramp and Finland Drive intersections. The finding operational and safety analysis and the FHWA Policy Point discussion are summarized as follows:
Purpose and Need
• During the existing PM peak, congestion at the Saxon Boulevard/Finland Drive intersection and on the I-4 eastbound off-ramp to Saxon Boulevard eastbound cause queuing back to the I-4 mainline gore point, creating a safety concern.
• The purpose of this project is to provide operational and safety improvements at the eastbound I-4 to eastbound Saxon Boulevard off-ramp intersection to relieve congestion and mitigate the risk of queuing on the off-ramp back to the I-4 mainline.
Future Safety Performance
• Signalization will introduce traffic control at the merging conflict area and allow for gaps in traffic along Saxon Boulevard, improving safety where the off-ramp joins eastbound Saxon Boulevard.
• The realignment of the off-ramp will eliminate the merge conflict and reduce the skew angle to improve the driver view at the intersection.
• Widening the ramp to two lanes (downstream of the gore area) will effectively double the queue storage and the service capacity through the signal, reducing the queue spillback from Saxon Boulevard toward the I-4 mainline and reducing the potential for high-speed rear end crashes along the I-4 mainline.
Purpose and Need
Download the Purpose and Need (PDF, 110.1KB)
The purpose of this project is to provide operational and safety improvements at the interchange at I-4 and Saxon Boulevard. Currently, the interchange is a partial cloverleaf, with loop ramps in the NE, NW and SW quadrants. A collector/distributor road exists on I-4 westbound to safely accommodate the weave movement between the NW and SW loop ramps.
All of the off-ramps are single lane ramps operating as free-flow movements, except the westbound I-4 to westbound Saxon Boulevard off-ramp, which is stop-controlled. During the existing PM peak, congestion is present on the eastbound I-4 to eastbound Saxon Boulevard off-ramp, as well as at the Saxon Boulevard/Finland Drive intersection immediately downstream. Eastbound queues form along Saxon Boulevard and impact the operations of the eastbound off-ramp. The eastbound off-ramp is a free-flow ramp with approximately 1,300 feet of storage, but has a merge distance of approximately 250’ onto Saxon Boulevard.
Although it is free flow, the merge distance prevents vehicles from making this movement freely when eastbound volumes on Saxon Boulevard are high. This is especially true during the PM peak, when the ramp terminal essentially operates as stopcontrolled. The congestion on Saxon Boulevard and subsequent congestion on the I-4 eastbound offramp causes queuing back to the I-4 mainline gore point, creating a substantial safety concern.