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I-75 at Royal Palm Blvd (SR-93)

Download the Final Study (PDF, 14.6MB)

Executive Summary

The purpose of this study is to evaluate the traffic impact of a proposed Park and Ride Lot on the interchange of I-75 at Royal Palm Boulevard. The proposed Park and Ride Lot will be located in the southwest quadrant of the interchange adjacent to the I-75 southbound on-ramp and will provide access to planned I-75 Express Bus services.

A Methodology Letter of Understanding (MLOU) was prepared to outline the methodology for the analysis and evaluation of this Interchange Operational Analysis Report (IOAR). The MLOU was approved by the Florida Department of Transportation (FDOT) District 4 Interchange Review Coordinator (IRC) in August 2018. The traffic projections in the IOAR were developed using existing field traffic counts and the latest version of South East Regional Planning Model (SERPM) 7.071. SERPM 7.071 is calibrated to base year 2010 conditions and includes a horizon year of 2040. The analysis years for this study include Existing Year 2018, Opening Year 2020, and Design Year 2040. The operational analysis for this study was performed using the Highway Capacity Software (HCS) Version 7.7 (based on HCM 2000, HCM 2010 and HCM 6th Edition methodologies where appropriate) and Synchro Version 10.

The traffic impact of the Park and Ride Lot was evaluated for AM peak hour (8:00AM-9:00AM), PM Peak hour (5:00PM-6:00PM), and off-peak hours (7:00AM-8:00AM and 4:00PM-5:00PM). Based on the operational analysis of existing conditions, all the I-75 ramps are operating at LOS D or better. The intersection of Royal Palm Boulevard and Weston Road is operating at level of service (LOS) F during AM peak and off-peak hours, and LOS E during both PM peak and offpeak hours. The intersection of Royal Palm Boulevard and I-75 southbound off-ramp is operating at LOS D or better during AM peak hour, PM peak hour, and off-peak hours.

Crash analysis was performed using the five-year data from 2011 to 2015, the most current data are available at the time when the analysis was conducted. The crash data were obtained from the FDOT Crash Analysis Reporting System database and Signal Four Analytics. The crash analysis indicated that there were 257 crashes at Royal Palm Boulevard and Weston Road during the five year period. There was a total of 31 crashes on I-75 southbound on/off-ramps during the same period. The majority of the crashes were rear-end and sideswipe crashes. There were no fatal crashes.

Operational and safety analyses were performed for two alternatives: the No-Build and Build Alternatives. The No-Build Alternative includes the improvement recommended by the I-75 System Interchange Modification Report (SIMR) approved by FDOT in 2011. Specifically, a third right-turn lane is added on the southbound off-ramp. Also, the left-most westbound through lane is converted to a westbound left-turn lane at the intersection of Royal Palm Boulevard and Weston Road. The Build Alternative includes the proposed Park and Ride Lot and a new two-way south leg at the southbound off-ramp interchange terminus intersection to provide access to the Park and Ride Lot. A new signal timing plan was developed to address the new intersection configuration and new travel pattern.

Merge/diverge analyses were performed for the I-75 on- and off-ramps for the No-Build and Build Alternatives. Merge analysis for the passenger vehicles from the Park and Ride Lot to the I-75 southbound on-ramp was also conducted for the future Build conditions. The I-75 ramps will all operate at LOS D or better during AM and PM peak hours in future 2020 and 2040 No-Build conditions. The ramps will operate at the same LOS as the No-Build Alternative with the proposed Park and Ride Lot. The Park and Ride Lot will not cause a degradation in LOS on the I-75 ramps. The Park and Ride ramp merge analysis for years 2020 and 2040 shows that the ramp merge from the proposed Park and Ride Lot will operate at LOS C or better during the AM and PM peak periods in 2020 and 2040.

In 2040 under No-Build conditions, the intersection of Royal Palm Boulevard and I-75 southbound off-ramp will operate at LOS E with an average delay of 71.8 seconds during AM peak hour. The intersection will operate at LOS B during PM peak hour. The 95th-percentile queue length on I-75 southbound off-ramp will be 705 feet and 349 feet during AM and PM peak hours, respectively.

With the proposed Park and Ride Lot, this intersection will operate at LOS E with an average delay of 74.9 seconds during AM peak hour and LOS D during PM peak hour. The average delay will increase by 3.1 seconds compared to the No-Build Alternative during AM peak hour. The 95th percentile queue length on I-75 southbound off-ramp will be 657 feet and 437 during AM and PM peak hour with the Park and Ride Lot in 2040, respectively. The length of the existing I-75 southbound off-ramp is 1,938 feet. The queue on I-75 southbound off-ramp will not extend to I-75 mainline.

The intersection of Royal Palm Boulevard and Weston Road will operate at LOS F during AM and PM peak hours for the No-Build Alternative in 2040. With the Park and Ride Lot, the intersection will operate at the same LOS with an additional delay of 3.0 seconds and 1.8 seconds during AMand PM peak hours, respectively.

In summary, based on the operational analysis, with the proposed Park and Ride Lot, the queue on I-75 southbound off-ramp will not extend to I-75 mainline. The proposed Park and Ride Lot will not cause degradation in LOS on the I-75 ramps, the ramp terminus, and the adjacent intersection. The Highway Safety Manual (HSM) methodology was used to predict the number of crashes in 2040. The predicted number of crashes at the interchange terminus would be 11.67 for the No-Build Alternative and 13.444 for the Build Alternative in 2040. There is no apparent difference in the safety performance of the ramp terminus with the proposed modifications under the Build Alternative.

The Federal Highway Administration (FHWA) Interchange Access Policy was checked to assure that the adequate level of service is provided in terms of safety and mobility. The proposed Park and Ride Lot is not anticipated to have an adverse impact on the safety and operations of mainline I-75, the interchange terminus, and the intersection of Royal Palm Boulevard and Weston Road.

The proposed Park and Ride Lot will also provide full access and accommodate all traffic movements between Royal Palm Boulevard and I-75. The proposed modifications are designed to meet current standards for federal-aid projects on the interstate system and conform to American Association of State and Transportation Officials (AASHTO) and the FDOT design standards. District 4 will closely monitor the I-75 ramps and intersections operating conditions after the Park and Ride Lot is built. Improvements and/or modifications will be made to the Park and Ride Lot if issues arise.

Purpose and Need

Download the Purpose and Need (PDF, 65.3KB)

The Express Bus services were developed in South Florida to enhance mobility and vehicle throughput in the region. As part of the agreement between FDOT with the Broward Metropolitan Planning Organization (BMPO), the Express Bus services will be provided as an alternative travel choice to Express Lanes. In its efforts to implement the agreement, FDOT District 4 has partnered with cities and municipalities in Broward County to provide Express Bus services to commuters travelling to region’s major destinations such as Downtown Miami, Brickell Center, and the Miami Health District. With I-75 Express Lanes open to traffic in western Broward County and northwest Miami-Dade County, FDOT conducted a series of studies to identify potential riders and expand the Express Bus services to maximize the benefits of the Express Lanes. The studies determined that the area of I-75 and Royal Palm Boulevard would be a potential location to build a Park and Ride Lot for future Express Bus services serving Miami International Airport and its surrounding areas. A further study developed a conceptual plan that would place the Park and Ride Lot in the southwest quadrant of the I-75/Royal Palm Boulevard Interchange between the I-75 Southbound on-ramp and I-75 mainline. The Park and Ride Lot would contain 160 parking spaces including six (6) Americans with Disabilities Act (ADA) accessible spaces. The I-75 southbound off-ramp terminus would be modified to provide access to the Park and Ride Lot from both east and west side of Royal Palm Boulevard. A merge lane would be provided to connect the Park and Ride Lot to the I-75 Southbound on-ramp, so buses and other vehicles could enter I-75 southbound mainline and the Express Lanes. The conceptual plan was presented to the District Interchange Review Coordinator (DIRC) and received approval from FDOT District 4 Acting Secretary on January 11th, 2018. Additionally, based on the study, the proposed southbound Express Bus service connecting the Weston area and Miami International Airport (MIA) will operate from 4:00 AM to 7:00 AM with a peak hour headway of 30 minutes. The northbound Express Bus service is proposed to operate from 1:00 PM to 4:00 PM with the same peak hour headway of 30 minutes. Intersection improvements, including signal timing changes, at the I-75 and Royal Palm Boulevard interchange area will be included as the Build Alternative for the IOAR. The final design of the Park and Ride facility will be performed as an integral part of the Royal Palm Boulevard interchange improvements project (FPID 421548-1).

The IOAR will evaluate the impacts of the proposed Park and Ride Lot on the traffic operations at the I-75 and Royal Palm Boulevard ramp terminus and the Weston Road at Royal Palm Boulevard intersection. The IOAR will be conducted in coordination with: 1) FDOT’s ongoing design project to improve Royal Palm Boulevard of I-75; and 2) the previously approved I-75 SIMR that included proposed improvements to the I-75 Royal Palm Boulevard interchange.

The purpose of preparing the Interchange Operational Analysis Report for the I-75 at Royal Palm Boulevard Interchange is to document the operational and safety impacts of the proposed Park and Ride Lot to be built in the southwest quadrant of the interchange and the adjacent intersections.

The I-75 southbound off-ramp terminus at the I-75/Royal Palm Boulevard interchange is currently operating at LOS D or better during both AM and PM peak hours, but the southbound right-turning movement is experiencing significant delays in the AM peak period with an average delay of more than 90 seconds and operating at LOS F.

The intersection of Weston Road and Royal Palm Boulevard is currently operating at LOS F in the AM peak period. The LOS for the eastbound, westbound, and southbound approaches is E or F during AM peak period. The westbound left-turning movement is experiencing delays of approximately 200 seconds in the AM peak period. During PM peak period, this intersection is operating at LOS E. All four approaches are operating at LOS E or F. These delays are expected to worsen in the future with the projected growth in traffic in the area. The improvements being implemented as mentioned above are expected to provide relief for traffic congestion in the area, but the impact of proposed Park and Ride Lot on the interchange is yet to be determined. The goal of this study is to conduct a comprehensive analysis of the impacts of these improvements and the proposed Park and Ride Lot when the Express Bus is operating, recommend additional improvements or alternatives if necessary, and seek approval of engineering and operational acceptability for implementation.

The need for this project relates to the following:
• Ensure that the proposed Park and Ride facility will not significantly impact the interchange operations,

• Ensure that the proposed access from/to the proposed Park and Ride facility will not cause any unsafe conditions in traffic operations and circulations.

The overall objectives of this project include the following elements:
• Maintain safety, mobility and circulation of the interchange

• Address potential operational, safety, and physical deficiencies of the interchange caused by the proposed Park and Ride facility.

Recommended Alternative

Download the Recommended Alternative (PDF, 286.7KB)

Please see the attached recommended alternative

Travel Time Savings

Safety Benefits