Download the Executive Summary (PDF, 571.1KB)
The Florida Department of Transportation (FDOT) District One requests the FDOT Systems Implementation Office approval of an Interchange Operational Analysis Report (IOAR) for the improvement of the Interstate 4 (I-4) interchange at State Road 33 (SR 33) in Polk County. This IOAR has
been developed in accordance with FDOT Policy No. 000-525-015: Approval of New or Modified Access to Limited Access Highways on the State Highway System (SHS), FDOT Procedure No. 525-030-160: Approval of New or Modified interchange access to limited facilities on SHS, the Interchange Access Request User’s Guide (2018) and the FDOT’s 2019 Project Traffic Forecasting Handbook (Procedure No. 525-030-120).
The I-4/SR 33 interchange is located within the City of Lakeland in the northwest portion of Polk County, Florida. I-4 is a six-lane divided east-west limited access facility with a posted speed limit of 70 miles per hour (mph). I-4 is functionally classified as an Urban Principal Arterial-Interstate. SR 33 is a two-lane undivided roadway both north and south of the I-4 interchange and has a posted speed limit of 60 mph. SR 33 is functionally classified as an Urban Minor Arterial. Within the interchange area, SR 33 is a two lane divided roadway. The existing I-4/SR 33 interchange is a rural diamond interchange configuration that has single lane on- and off-ramps and two unsignalized ramp terminal intersections.
The final design phase of the I-4/SR 33 interchange improvement was initiated in June 2014 and included traffic signals at both I-4 ramp terminal intersections. Based on an additional evaluation initiated in August 2016, District One decided to modify the final design plans for the interchange and replace the
signalized intersections with roundabouts. A subsequent IOAR, approved in June 2019, reevaluated the design alternatives for the interchange (signalization and roundabouts) under a 2025 opening year and 2045 design year and ultimately recommended the construction of roundabouts at the ramp terminal intersections.
The roundabout improvements are expected to be let for construction in 2027. This IOAR evaluates interim operational improvements (Build Alternative) at the ramp terminal intersections consisting of the addition of traffic signals while maintaining the existing geometry. Based on the traffic and safety analyses, the Build Alternative will improve traffic operations, reduce queue lengths, and reduce the number of crashes predicted to occur over the seven-year lifespan of the improvements. The request for approval of this revised access point, and the analyses and evaluations that were conducted to support this request, satisfies FHWA’s two policy point requirements as discussed below. Therefore, the Build Alternative is recommended for implementation at the I-4/SR 33 interchange.
Purpose and Need
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The District and local government stakeholders have identified operational deficiencies associated with an increase in traffic for the current configuration and a solution has been identified to construct roundabouts at the interchange ramp terminal intersections. Before the recommended solution is
implemented, it has been proposed that signals be installed at the ramp terminal intersections in the interim to alleviate current off-ramp queueing issues. Eastbound off-ramp queues have been observed to spill onto the eastbound I-4 mainline during the peak hours of a typical weekday, causing an operational and safety deficiency. The purpose of this IOAR is to evaluate the future traffic operations at the I-4/SR 33 interchange under the interim condition of intersection signalization.