The intersection of Prairie Avenue, Chase Avenue, and 44^th Street currently operates as a two-way stop intersection. Chase Avenue and 44^th Street are stop-controlled while Prairie Avenue traffic is uncontrolled.  The intersection is currently designed with a stop-controlled crosswalk on the east leg and a marked crosswalk on the north leg with a pedestrian crossing sign.  The intersection is adjacent to North Beach Elementary School and Muss Park.  Currently there is no sidewalk connecting to the southwest corner of the intersection, therefore no crosswalks exist at the west and south legs of the intersection (attachment).  As part of a recently completed Safe Routes to School Project managed by the Transportation and Mobility Department, the pavement markings, and pedestrian crossing signs were upgraded.

In May 2018, pursuant to a request received through the Mayor’s office, the City conducted a warrant analysis for multi-way stop control at the intersection of Prairie Avenue and 44^th Street/Chase Avenue. Based on the data collected, the intersection did not meet any of the minimum criteria to warrant an all-way stop.

At the May 8, 2019 City Commission meeting, Commissioner Steinberg sponsored the referral of a discussion item regarding the intersection of 44^th Street/Chase Avenue and Prairie Avenue as it relates to safety and the possibility of additional stop signs to the June 19, 2019 Neighborhood/Community Affairs Committee.  The item was deferred at the October 23, 2019 meeting to allow for data collection and a warrant analysis to be completed once school traffic had normalized.  

The evaluating criteria for multi-way stop signs is outlined in the U.S. Department of Transportation Federal Highway Administration’s Manual on Uniform Traffic Control Devices (MUTCD). The MUTCD specifies the minimum criteria that must be met prior to installation of a multi-way stop control at an intersection. The criteria are based on crashes and volumes (vehicular, pedestrian, and bicycle) at an intersection over various periods of time.

The approval, implementation, and maintenance of traffic control devices is under the jurisdiction of Miami-Dade County; however, to expedite the approval process, City’s Transportation and Mobility Department staff conducts most of the warrant analyses for multi-way stop control, pedestrian flashing beacons, and traffic signals in-house and works with the County to expedite the installation, if warranted.

According to the 2019 City of Miami Beach Resident Survey, 74% of respondents expressed that they are most concerned/dissatisfied with pedestrian safety (vehicles not yielding to pedestrians) when crossing an intersection.

Based on the peak periods identified through continuous 48-hour traffic volume counts, the Transportation and Mobility Department staff engaged a traffic consultant to collect data (vehicular, pedestrian, and bicycle counts).  Given that the intersection experiences its highest traffic volumes on Wednesdays due to the elementary school schedule, all counts were collected on Wednesday, October 16, 2019.  In addition to the traffic data collected, staff also gathered crash data for the intersection for the past 12 months.

As outlined in the MUTCD, the following criteria must be met for an intersection to meet the warrants for a multi-way stop control:

1. Five or more reported crashes in a 12-month period that are susceptible to correction by a multi-way stop; or

2. The vehicular volume entering the intersection from the major street approaches (total of both approaches) averages at least 300 vehicles per hour for any 8 hours of an average day; and

3. The combined vehicular, pedestrian, and bicycle volume entering the intersection from the minor street approaches (total of both approaches) averages at least 200 units per hour for the same 8 hours, with an average delay to minor-street vehicular traffic of at least 30 seconds per vehicle during the highest hour.

The warrant analysis resulted in the following:

1. Crash warrant – 0 crashes (does not meet criteria)

2. Major movement (Prairie Avenue) 8-hour average vehicular volume – 151 vehicles (does not meet criteria)

3. Minor movement (44^th Street/Chase Avenue) 8-hour average vehicular, bicycle, pedestrian volumes – 93 vehicles, bicycles, pedestrians (does not meet criteria)

Based on the data collected and the warrant analysis following the methodology outlined in the MUTCD, the intersection of Prairie Avenue and 44^th Street was found to not be warranted.

Speed Analysis

In addition to the traffic volume data collection, 24-hour directional speed counts were collected for northbound and southbound traffic on Prairie Avenue.  The results of the speed data collection effort demonstrated an 85^th percentile speed of 29.5 MPH for the southbound vehicles, and 33 MPH for northbound vehicles.  The 85^th percentile speed represents the top speed or below at which 85 percent of drivers travel through the intersection.  The posted speed limit along Prairie Avenue is 30 MPH; however, the City is currently working on the deployment of 25 MPH for residential roads.

Given that the intersection is part of the existing school zone for North Beach Elementary, school zone beacons and signage are posted on Prairie Avenue advising of the 15 MPH speed limit during the hours of 7:15 AM – 9:15 AM and 1:45 PM – 3:30 PM.  The Transportation and Mobility Department conducted a vehicular speed analysis to isolate the 85^th percentile speed during the school zone times.  Based on the analysis, it was found that the 85^th percentile speed during school zone times is 29 MPH for northbound vehicles and 28 MPH for southbound vehicles, significantly exceeding to posted school zone speed limit.

The speed data has been shared with the area captain, and motor officers will be deployed during the school zone hours to enforce speed violations.

Safe Routes to School

Given the proximity to the school, the City contacted the County to inquire about warranting the multi-way stop control if the intersection is part of a Safe Route to School. The County advised that the installation of the multi-way stop sign would still need to meet the MUTCD criteria to warrant installation.  County staff advised that if the multi-way stop sign was installed without meeting the proper warrants, it would introduce a concern of low compliance which could become a safety issue.