4Agenda Item No:4.
City Commission Agenda Item Report
Meeting Date: December 1, 2020
Submitted by: Aurelio Carmenates
Submitting Department: Public Works & Engineering
Item Type: Resolution
Agenda Section:
Subject:
A Resolution authorizing the City Manager to negotiate and enter into a contract with Maggolc Inc., for the
construction of a traffic calming speed table at SW 78th Street West of SW 62nd Avenue. 3/5 (City
Manager-Public Works & Engineering)
Suggested Action:
Attachments:
Memo SW 78st W 62av 11-24.docx
Reso SW 78st W 62av 11-24.docx
Maggolc- Contract Speed Table.pdf
Maggolc Inc Speed Table - Price Proposal.pdf
SOMI Traffic Calming Study_SW 78 St.pdf
SW 78th Street Speed Table RESIDENT SURVEY.pdf
Amendment No.1 to the Intergovernmental Agreement EXECUTED.pdf
1
CITY OF SOUTH MIAMI
OFFICE OF THE CITY MANAGER
INTER-OFFICE MEMORANDUM
TO:The Honorable Mayor & Members of the City Commission
FROM:Shari Kamali, City Manager
DATE:December 1, 2020
SUBJECT:A Resolution authorizing the City Manager to negotiate and enter into a contract with
Maggolc Inc., for the construction of a traffic calming speed table at SW 78
th Street
West of SW 62nd Avenue.
BACKGROUND:The City desires to provide traffic calming devices to convey speed reduction and
safety to the West Pinecrest neighborhood. The City completed a traffic study report
and executed an amendment to the Intergovernmental Traffic Agreement with
Miami-Dade County which allows the City responsibilities of certain traffic engineering
functions. In order to meet the Miami-Dade County’s traffic flow modifications
requirements the City submitted a survey to the residents for approval of a propose
traffic calming measure. The residents responded to the survey in concurrence to
implement a traffic calming measure on SW 78th Street West of SW 62nd Avenue. To
convey speed reduction and safety, the City developed construction scope documents
following Miami-Dade County Standards for the construction of a traffic speed table at
SW 78th Street West of SW 62
nd Avenue. Quotes were solicited from several
contractors beginning on November 13, 2020.
The City received a total of three (3) proposals in response to a quotation. Pursuant to
review, it was determined that Maggolc Inc., is the most responsive and responsible
bidder for this proposal. Below are the top three proposals received:
Contractor Bid Price
Maggolc Inc.$7,200.00
V Engineering & Consulting Corp.$10,400.00
Metro Express, Inc.$12,997.00
A contingency amount of $800 will be included over the proposal amount of $7,200 to
address for unknown factors that may arise during the work.
AMOUNT:Amount not to exceed $8,000 which includes $800 for contingency.
FUND &ACCOUNT:The expenditure shall be charged $8,000 to the People Transportation Tax Fund
account number 124-1730-541-6490 which has a balance of $571,563.66 prior to this
request.
ATTACHMENTS:Resolution
Construction Contract with Exhibits
Maggolc Inc., Bid Documents
Traffic Calming Study
Miami-Dade County Amendment#1 to the Intergovernmental Agreement
Resident Survey
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Page 1 of 2
RESOLUTION NO.:______________________1
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A Resolution authorizing the City Manager to negotiate and enter into a contract with Maggolc, 3
Inc., for the construction of a traffic calming speed table at SW 78th Street West of SW 62nd 4
Avenue.5
WHEREAS,the City Mayor and Commission desire to provide traffic calming devices to convey speed 6
reduction and safety to the West Pinecrest neighborhood; and 7
WHEREAS, the west Pinecrest Traffic Calming Project has been budgeted in the Capital Improvement 8
Program section of the City’s budget; and9
WHEREAS, the City completed a traffic study report and executed an amendment to the 10
Intergovernmental Traffic Agreement with Miami-Dade County which allows the City responsibilities of certain 11
traffic engineering functions; and12
WHEREAS, the City conducted a survey following up to the traffic study report to adhere with Miami-Dade 13
County’s traffic flow modifications and street closure procedures and received approval from the residents of the 14
area to install a speed table; and15
WHEREAS,to convey speed reduction and safety to the West Pinecrest neighborhood, the City developed 16
construction scope documentsfollowing Miami-Dade County standardsfor the construction of a trafficspeed table 17
at SW 78th Street West of SW 62nd Avenue; and18
WHEREAS,quotes were solicited on November 13, 2020 and the City received a total of three (3) cost 19
proposal in response to the solicitation; and20
WHEREAS,pursuant to a competitive selection process, it was determined that Maggolc Inc., submitted a 21
proposal in the amount of $ 7,200 that was the most cost effective; and22
WHEREAS,the City desires to provide a contingency of $800 over the proposal amount to address for 23
unknown factors that may arise during the work; and24
WHEREAS, the Mayor and City Commission desire to authorize the City Manager to negotiate and enter 25
into a contract with Maggolc Inc.,for the construction of a traffic calming speed table at SW 78th Street West of SW 26
62nd Avenue for a total amount not to exceed $8,000 which includes a $800 contingency. 27
WHEREAS, the expense for this project shall be charged to the People Transportation Tax Fund account 28
number 124-1730-541-6490 which has a balance of $571,563.66 prior to this request.29
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NOW THEREFORE, BE IT RESOLVED BY THE MAYOR AND CITY COMMISSIONERS OF THE CITY OF SOUTH 31
MIAMI, FLORIDA:32
Section 1. The foregoing recitals are hereby ratified and confirmed as being true and they are incorporated 33
into this resolution by reference as if set forth in full herein.34
Section 2.The City Manager is authorized to negotiate the price, terms and conditions and to execute a 35
contract with Maggolc Inc., for the construction of a traffic calming speed table at SW 78
th Street West of SW 62nd36
Avenue for a total amount not to exceed $8,000. The City Manager is authorized to expend up to $800 to address 37
any condition that the contractor, using reasonable diligence, could not have foreseen when formulating its bid. A 38
3
Page 2 of 2
copy of the approved form of contract is attached. The expenditure shall be charged to the People Transportation 1
Tax Fund account number 124-1730-541-6490 which has a balance of $571,563.66 prior to this request.2
Section 3. Corrections. Conforming language or technical scrivener-type corrections may be made by the 3
City Attorney for any conforming amendments to be incorporated into the final resolution for signature.4
Section 4:Severability.If any section, clause, sentence, or phrase of this resolution is for any reason held 5
invalid or unconstitutional by a court of competent jurisdiction, the holding shall not affect the validity of the 6
remaining portions of this resolution. 7
8
Section 5: Effective Date:This resolution shall become effective immediately upon adoption. 9
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PASSED AND ADOPTED this _____ day of_______________, 2020. 11
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ATTEST: APPROVED: 13
14
___________________________________________15
CITY CLERK MAYOR16
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READ AND APPROVED AS TO FORM,COMMISSION VOTE: 18
LANGUAGE, LEGALITY AND EXECUTION Mayor Philips: 19
THEREOF Vice Mayor Welsh:20
Commissioner Harris:21
___________________________Commissioner Liebman: 22
CITY ATTORNEY Commissioner Gil:23
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ENGINEERING CONTRACTOR – LIC: E-251302
11020 SW 55 ST., MIAMI, FL 33165
PHONE: 786-291-2949 FAX: 786-472-8831
maggolc@yahoo.com
PROPOSAL
November 9, 2020
To:
Aurelio Carmenates, P.E.
Capital Improvements Program Project Manager
Public Works Engineering & Construction Division
City of South Miami
Project: Construction of one (1) Speed Table along SW 78th Street between 6220/6227.
Proposal Includes:
1. Mobilization and MOT
2. Milling Existing Asphalt 1.5”
3. Superpave Asphalt Concrete SP-9.5
4. Temporary & Thermoplastic Striping
5. Signs
6. Restoration and clean the construction area
7. As Built Survey Plan
LS Price Proposed: $ 7,200.00
Construcion Time: 15 days
Thank You for the opportunity,
Sincerely,
Mario Gonzalez
Maggolc Inc./ President
43
March 20th, 2019
City of South Miami
Traffic Calming Study
SW 78th Street
(US 1 - SW 62nd Avenue)
South Miami, Florida
Richard Garcia & Associates, Inc.
44
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RICHARD GARCIA & ASSOCIATES, INC. Page iii
TABLE OF CONTENTS
Engineer’s Certification .......................................................................................... ii
Executive Summary ................................................................................................ 1
Introduction ............................................................................................................. 3
Study Area / Description ..................................................................................................... 3
Traffic Data .............................................................................................................. 4
Average Daily Traffic (ADT) & Peak Hour Volumes ......................................................... 4
Vehicle Speed Data ............................................................................................................ 4
Level of Service (LOS) .......................................................................................................... 4
Traffic Calming Measures ...................................................................................... 7
Levels of Traffic Calming ..................................................................................................... 7
Level I ............................................................................................................................................... 7
Level II .............................................................................................................................................. 8
Level III............................................................................................................................................ 10
Traffic Calming Analysis (Phase 2) ...................................................................... 12
Traffic Calming Criteria & Thresholds ............................................................................... 12
Traffic Calming Evaluation & Appraisal .......................................................................... 13
Minimum Traffic Volume ............................................................................................................. 13
85th Percentile Speed ................................................................................................................. 14
Correctable Accidents, Cut Through Traffic & Pedestrian Crossing Volume ..................... 14
Municipal Boundary Considerations ......................................................................................... 15
Conclusion ............................................................................................................ 16
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LIST OF FIGURES
Figure 1: Study Area ................................................................................................................. 3
Figure 2: Roadway Links & Traffic Data ................................................................................ 6
LIST OF TABLES
Table 1: Summary of Traffic Calming Evaluation ................................................................ 2
Table 2: Average Daily Traffic (ADT) ..................................................................................... 5
Table 3: Roadway Traffic Volumes - AM Peak Hour ........................................................... 5
Table 4: Roadway Traffic Volumes - PM Peak Hour ........................................................... 5
Table 5: Miami-Dade County Policy for Traffic Calming Measures ............................... 13
Table 6: Minimum Traffic Volume Criterion ........................................................................ 14
Table 7: 85th Percentile Speed Criterion ............................................................................. 15
APPENDICES
Appendix 1: Traffic Data (Volume & Speed Data) & Adjustment Factor
Appendix 2: MDCPWD Traffic Calming Criteria
Appendix 3: Analysis & Evaluation of Traffic Calming Criteria
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Executive Summary
The main objective of this study is to evaluate the existing traffic conditions and to
determine whether traffic calming devices should be considered at the studied
corridor, SW 78th Street between US 1 (SR 5) and SW 62nd Avenue. SW 78th Street
within the study limits is a two-lane (undivided) local street that provides
connectivity in the east-west direction. This roadway is mainly surrounded by
residential and has a posted speed limit of 25 miles per hour (MPH). This study has
been performed consistent with Phase 2 (Traffic Study by Applicant's Consultant) as
identified in the Miami-Dade County’s Traffic Flow Modification(s)/Street Closure(s)
Procedure.
The data collection consisted of 48-hour Automatic Traffic Recorder (ATR) counts
and 24-hour Speed data at three roadway links within the study area. These traffic
counts were performed from Wednesday, February 27th through Thursday, February
28th, 2019. The existing traffic data was utilized in the evaluation of the Miami-Dade
County Public Works Department (MDCPWD) traffic calming criteria.
The governing standard utilized in this analysis was Miami-Dade County’s Traffic
Flow Modification(s)/Street Closure(s) Procedure. Although the referenced manual
identifies two phases (i.e. Phase 1 & Phase 2), this traffic study followed the Phase 2
procedure which is initiated by the applicant, in this case the City of South Miami.
Note, Phase 1 is an analysis/study initiated and performed by MDCPWD.
As indicated in the MDCPWD referenced manual, Traffic Calming Measures on
neighborhood streets may be considered if a traffic study finds sufficient
justification. As such, the study area was evaluated in an effort to identify any
traffic intrusion, excessive traffic volume, speeding, traffic accidents, etc and to
determine if the traffic data meets the MDCPWD first traffic calming criteria and at
least one of the remaining criteria as shown in Table 1.
The first or “Primary Criteria” is Minimum Traffic Volumes. This criterion is met when
the traffic volumes exceed 1,500 vehicles per day or 150 vehicles during the peak
hour. As a result, the traffic data exceeded the Minimum Traffic Volume threshold
for Residential Local Streets and therefore, the first criterion is met.
The “Second Criteria” includes several traffic measures such as the 85th Percentile
Speed, Correctable Accidents, Cut Through Traffic and Pedestrian Crossing
Volume. The 85th percentile speed criterion was evaluated to determine if the
existing vehicular speed is a concern at the studied locations. A speeding issue
can be identified when the 85th percentile speed of all vehicles is at least 10 miles
per hour (MPH) greater than the posted speed. The posted speed within the study
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Other Criterion:
85th Percentile Speed
No. Name AM Peak PM Peak
85th Percentile Speed:
10 MPH > Posted Speed Limit
1
Peak Hour Volume > 150 VPH
Primary Criterion:
Minimum Traffic Volume
At
Roadway Link
3MET
NOT MET MET2SW 78 Street
west of SW 63 Avenue
(South Miami Elks Drive -
SW 63 Avenue)
MET
NOT MET MET NONOT METSW 78 Street west of SW 62 Avenue
(SW 63 Avenue - SW 62 Avenue)
NO
NOT MET MET NOSW 78 Street east of US 1
(US1 - South Miami Elks Drive)MET
Traffic
Calming
Measure
(Met Both
Criterion)ADT > 1,500 VPD
NOT MET
NOT MET
area is 25 MPH and therefore, the 85th percentile speed data must reveal 35 MPH
or greater to meet this criterion. Based on the existing speed data, the highest 85th
percentile speed within the study area is 28 MPH and does not meet the speed
criterion. Table 1 summarizes the evaluation of the policy of traffic calming
measures.
Although no data was gathered to quantify accidents, cut through traffic and
pedestrian volume, our field observations revealed there are no issues regarding
the referenced criteria. However, in addition to the above, the following
observations were made during the field review:
No evidence of crashes or accidents
No cut through traffic was identified
Pedestrian volume was low to nonexistent
Therefore, this study assumes that the study area does not meet the criterion of
Correctable Accidents, Cut Through Traffic and Pedestrian Crossing Volume.
In conclusion, the traffic calming analysis documented in this report reveals that SW
78th Street (between US 1 - SW 62nd Avenue) did satisfy the MDCPWD first traffic
calming criteria (Minimum Traffic Volume) but no other criterion was met. However,
the City may choose to obtain a two-thirds (2/3) concurrence from affected
residents or pass a resolution as indicated on Table 5 and the Municipal Boundary
Considerations section of this report (page 15). If either is secured by the City, we
would recommend the following traffic calming options:
Traffic Circle at SW 78th Street & SW 63 Avenue/SM Elks Drive
Traffic Circle at SW 78th Street & SW 63 Avenue
Midblock Traffic Calming on SW 78th Street between SW 62nd & 63rd Avenue
Choker or Neckdown/Narrowing traffic lanes
Table 1: Summary of Traffic Calming Evaluation
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Introduction
The purpose of this study is to evaluate the existing traffic conditions and to
determine whether traffic calming devices should be considered at the studied
corridor, SW 78th Street between US 1 (SR 5) and SW 62nd Avenue. This study has
been performed consistent with Phase 2 (Traffic Study by Applicant's Consultant) as
identified in the Miami-Dade County’s Traffic Flow Modification(s)/Street Closure(s)
Procedure.
Study Area / Description
As previously mentioned, the study area is the corridor of SW 78th Street US 1 and
SW 62nd Avenue in the City of South Miami, Florida. SW 78th Street within the study
limits is a two-lane (undivided) local street that provides connectivity in the east-
west direction. This roadway is mainly surrounded by residential and has a posted
speed limit of 25 miles per hour (MPH). Figure 1 below depicts the study area.
Figure 1: Study Area
Study
Area
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Traffic Data
The data collection consisted of 48-hour Automatic Traffic Recorder
(ATR) counts and 24-hour Speed data. These traffic counts were
performed from Wednesday, February 27th through Thursday, February
28th, 2019. Figure 2 depicts the study area and includes the traffic data
for each roadway link. Moreover, the 48-hour traffic volumes were collected in 15-
minute intervals while the 24-hour speed data was gathered in one-hour intervals.
The data collection was performed at the locations as follows:
1. SW 78th Street, east of US 1
2. SW 78th Street, west of SW 63rd Avenue
3. SW 78th Street, west of SW 62nd Avenue
Average Daily Traffic (ADT) & Peak Hour Volumes
The 48-hour traffic counts were utilized to determine the Average Daily Traffic (ADT)
and Peak Hour volumes at each roadway link identified above. The traffic counts
were averaged, adjusted for seasonal variations and utilized in the evaluation of
the MDCPWD traffic calming criteria. Table 2 summarizes the Average Daily Traffic
(ADT). Tables 3 and 4 contains the traffic volumes for the AM and PM peak hour,
respectively.
Vehicle Speed Data
Similarly, the 24-hour speed data was collected at each roadway link and
direction. The average speed and 85th percentile speed was summarized in Table 5
and also utilized in the evaluation of the MDCPWD traffic calming criteria.
Appendix 2 contains the speed data sheets.
Level of Service (LOS)
Additionally, the AM and PM peak hour traffic volumes were evaluated for Level of
Service (LOS) by the using the generalized Table 4 of the 2013 FDOT (Florida
Department of Transportation) Quality / Level of Service Handbook. As a result, the
study corridor is operating at acceptable LOS C during both the AM and PM peak
hour.
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No. Name Direction Day 1 Day 2 Average
EB9911003997 987
WB 1,047 1,130 1089 1078
Link 2,038 2,133 2,086 2,065
EB 783 837 810 802
WB 950 1,055 1003 992
Link 1,733 1,892 1,813 1,794
EB 624 632 628 622
WB 1,067 1,161 1114 1103
Link 1,691 1,793 1,742 1,725
At
Traffic Data (vehicles per day)ADT
Calculation
SW 78 Street
SW 78 Street
east of US 1
(US1 - South Miami Elks Drive)
3
Roadway Link
2 SW 78 Street
west of SW 63 Avenue
(South Miami Elks Drive -
SW 63 Avenue)
west of SW 62 Avenue
(SW 63 Avenue - SW 62 Avenue)
1
No. Name Direction Day 1 Day 2 Average
EB 61 55 58 57
WB 62 61 62 61
Link 121 108 115 113
EB 53 54 54 53
WB 53 53 53 52
Link 92 96 94 93
EB 66 62 64 63
WB 54 49 52 51
Link 97 99 98 97
C
C
C
2 SW 78 Street
west of SW 63 Avenue
(South Miami Elks Drive -
SW 63 Avenue)
3 SW 78 Street west of SW 62 Avenue
(SW 63 Avenue - SW 62 Avenue)
Roadway Link
At
1 SW 78 Street east of US 1
(US1 - South Miami Elks Drive)
Traffic Data (vehicles per hour) - AM Peak
Seasonally
Adjusted Peak
Hour Volumes
(2019)
Two-Way
Volume
Level of Service
No. Name Direction Day 1 Day 2 Average
EB10796102 100
WB 112 131 122 120
Link 171 198 185 183
EB 84 87 86 85
WB 164 173 169 167
Link 225 229 227 225
EB 57 59 58 57
WB 213 234 224 221
Link 246 257 252 249
Roadway Link Traffic Data (vehicles per hour) - PM Peak
Seasonally
Adjusted Peak
Hour Volumes
(2019)
Two-Way
Volume
Level of ServiceAt
1 SW 78 Street east of US 1
(US1 - South Miami Elks Drive)C
2 SW 78 Street
west of SW 63 Avenue
(South Miami Elks Drive -
SW 63 Avenue)
C
3 SW 78 Street west of SW 62 Avenue
(SW 63 Avenue - SW 62 Avenue)C
Table 2: Average Daily Traffic (ADT)
Table 3: Roadway Traffic Volumes - AM Peak Hour
Table 4: Roadway Traffic Volumes - PM Peak Hour
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23 MPH
ADT: 2,065 VPD
AM PEAK: EB: 57 VPH
WB: 61 VPH
PM PEAK: EB: 100 VPH
WB: 120 VPH
LOS C
21 MPH
21 MPH
23 MPH
28 MPH
27 MPH
ADT: 1,725 VPD
AM PEAK: EB: 63 VPH
WB: 51 VPH
PM PEAK: EB: 57 VPH
WB: 221 VPH
LOS C
ADT: 1,794 VPD
AM PEAK: EB: 53 VPH
WB: 52 VPH
PM PEAK: EB: 85 VPH
WB: 167 VPH
LOS C
Figure 2: Roadway Links & Traffic Data
XX MPH = 85TH PERCENTILE SPEED
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Traffic Calming Measures
Traffic calming is a system of design and management strategies that aim to
balance traffic on streets with other uses. This system was developed in Europe and
it is founded on the idea that streets should help create and preserve a sense of
place that their purpose is for people to walk, look, meet, play,
shop and even work alongside cars but not dominated by
them. The tools of traffic calming take a different approach
from treating the street only as a conduit for vehicles passing
through at the greatest possible speed. They include
techniques designed to lessen the impact of motor vehicle traffic by slowing it
down, or literally “calming” it. This helps build environment friendly to people on
foot.
Besides its power to improve the livability of a place, the strategies below can be
employed by painting lines, colors and patterns; using planters, bollards and other
removable barriers as suggested by the County; eliminating or adding parking; or
installing sidewalk extensions or similar structures with temporary materials. All
provide an opportunity to test devices, combinations and locations, fine-tuning the
approach according to results. Traffic calming, along with other small-scale
improvements, can enhance a place immediately, while being tested and refined
to meet long-term needs.
Levels of Traffic Calming
Miami-Dade County Traffic Flow Modification(s)/Street Closure(s) Procedure has
identified three levels of Traffic Calming. The goal of these levels is to provide a
framework of progressively increasing types of devices. Based on the level of traffic
restriction they provide; starting with the least restrictive (Level I) to the most
restrictive (Level III). All forms of Traffic Calming require a temporary
implementation followed by a re-evaluation of the effect before a final
(permanent) approval is granted.
Level I
The Level I is the least restrictive (passive) and most
common form of traffic calming. This level of
traffic calming measure is designed to restrain
traffic speed and lessen traffic impacts at the local
level, where traffic volumes, levels of service, and
network capacity are not an issue. The following
measures are categorized as Level I alternatives:
Education, neighborhood speed watch
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Law enforcement, movement restrictions
One-way streets, multi-way stop control
Textured pavement, gateway treatments
Border landscaping treatment
Level II
The Level II is designed to restrain traffic speed and lessen traffic impacts on traffic
routs, where traffic volumes, level of service and network capacity are or may
become an issue. This level incorporates traffic calming devices to include speed
restraints and street rearrangements on traffic routes through activity areas.
Moreover, the following bulleted items describe some of the physical devices for
Level II.
CHOKERS – BULBS – NECKDOWNS
Interchangeable terms for sidewalk extensions in
selected areas – such as at intersections or at mid-
block – as opposed to a full sidewalk widening. The
benefits:
Provide a refuge for pedestrians.
Shorten the crossing distance
Define parking bays
Deflect through traffic at a corner
Function as entry points
Provide space for amenities and enhancements (e.g. kiosks, trees, lighting)
ROUNDABOUTS
Large, raised, circular island at the middle of major
intersection, around which all oncoming vehicles
must travel until reaching their destination street,
where they then turn off. The benefits:
Create a “calmed” steady flow of traffic.
Reduction in conflict points, which can lead to
fewer accidents.
Traffic signals are not customarily required (although traffic control signs are
prominent).
Streets narrow as they approach the roundabout and crosswalk are installed on
these approaches – thereby slowing oncoming vehicles and giving pedestrians a
safe, obvious opportunity to cross.
Enhanced with fountains, sculpture or attractive landscaping, the island can serve
as a striking gateway.
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A sloping ramp around the perimeter of the raised island allows buses, trucks and
other large vehicles to maneuver the continuous curve while still maintaining a
lowered speed.
TRAFFIC CIRCLES
These small “mini-roundabouts” are designed for
small intersections, often used to slow traffic from
wide street into a smaller local street. Traffic
circles:
Help to slow down traffic in neighborhoods and
remind drivers that they must proceed carefully.
Help to sustain lowered vehicle speeds when
they’re used in a series.
Provide an opportunity for community activity in residential areas, where citizens can
create plantings or add other enhancements.
SPEED HUMPS AND SPEED TABLES
These devices reduce speed by introducing
modest up-and-down changes in the level of the
street, thereby requiring drivers to decelerate.
Speed Humps are rounded mounds,
approximately three inches high and 10 to 12
feet long. They effectively slow down traffic to
15-20 mph without making drivers
uncomfortable. For optimum speed reduction,
road humps need to be placed at frequent, designated intervals based on the
street’s dimensions, to minimize the tendency to accelerate between them. (Humps
are not to be confused with the speed bumps, which are usually at least 5-6” high
and less than three feet long).
Speed tables are road humps that are flat on top and sometimes slightly longer.
They are the same width as the street and rise to meet the grade of the sidewalk,
providing safe and comfortable crossing for walkers and wheelchairs (and greater
access for snow clearance than road humps). One benefit of speed tables is that
people cross at the point where drivers decrease speed.
It is important to highlight road humps, speed tables and cushions with clear
markings to alert approaching drivers. This can be accomplished by: painting
words and symbols directly on the street; changing the texture of the street surface;
or using signage (the word “Bump” instead of “Hump” is a standard approach
thought to effectively put drivers on the alert).
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MID-BLOCK RAISED MEDIANS / NARROWING TRAFFIC LANES
These techniques provide a flexible way to take
back space from the street for non-motor-vehicle
uses. Traditional traffic engineering calls for 12 to
13-foot lanes, citing “traffic safety” standards – but
newer evidence shows lanes as narrow as nine (9’)
feet can still be safe for driving.
Narrowing lanes and to widen sidewalks eases
crossing for pedestrian and gives them more space to walk.
Lanes can also be removed from serving traffic and designated for busses, trolleys or
other types of transit.
Traffic lanes can be transformed into bicycles lanes.
All street lanes can be narrowed together to create more room for non-auto uses.
Vertical elements like trees or bollards further reduce the “optical width” of a
narrowed street, thereby discouraging speeding.
CHICANES
Chicanes are sidewalk extensions that jog from one side of a street to the other to
replicate such a circuitous route. Below are of the benefits:
Narrow, curving roads encourage motorists to
drive more slowly and carefully.
A curvilinear path that interrupts a clear view and
compels drivers to slow down.
Chicanes can be formed using sculpture,
plantings and parking to enhance the
appearance and function of a street.
Diagonal parking and parallel parking can be
alternated to create a chicane effect.
Chicanes are best used on narrow roads to prevent vehicles from swinging out to
maintain their speed around the bends.
Level III
Similarly, Level III is designed to lessen traffic levels and impacts city-wide. This level
extends the term traffic calming to include a much wider range of traffic reduction
and control policies. This wide view interlaces traffic calming with urban transport
guidelines and away from its original focus on traffic management. This is the most
restrictive and most stringent traffic calming level and should be reserved as a last
resort. The following bulleted items describe some of the physical devices for Level
III.
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DIVERTERS
These physical barriers redirect traffic heading for a certain street onto a different
course, reducing vehicle overload on vulnerable (usually residential) streets overrun
by through traffic looking for shortcuts.
Diagonal Diverters traverse an entire intersection,
actually creating two unconnected streets that
each turn sharply away from one another.
Semi-Diverters restrict traffic in one direction to
prevent entrance to a street, while permitting
traffic to pass through in the other direction.
Although they effectively reduce traffic volume,
diverters must be part of a comprehensive
improvement scheme or else they can end up
simply displacing congestion.
STREET CLOSURE
The implementation of street closures is one of the
most restrictive traffic calming measures. This
treatment will redistribute traffic to other streets and
intersections. Additionally, access to the street
closed will limit access to adjacent properties and
may increase travel time and delay. This treatment
will require the most intense pre-implementation and
post-implementation analysis and should be left as a last resort.
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Traffic Calming Analysis (Phase 2)
This section will cover the analysis performed with the policy utilized to establish a
need for traffic calming measures. The governing standard utilized in this analysis
was Miami-Dade County’s Traffic Flow Modification(s) /Street Closure(s) Procedure.
Although the referenced manual identifies two phases (i.e. Phase 1 & Phase 2), this
traffic study followed the Phase 2 procedure which is initiated by applicant, in this
case the City of South Miami. Lastly, the Phase 1 procedure is an analysis/study
performed by Miami-Dade County Public Works Department (MDCPWD).
Traffic Calming Criteria & Thresholds
As indicated in the MDCPWD referenced manual, Traffic Calming Measures on
neighborhood streets may be considered if a traffic study finds sufficient
justification. As such, the study area was evaluated in an effort to identify any
traffic intrusion, excessive traffic volume, speeding, traffic accidents, etc and to
determine if the traffic data meets the MDCPWD first traffic calming criteria and at
least one of the remaining criteria as shown in Table 5 below.
The first or “Primary Criteria” is Minimum Traffic Volumes. These traffic volumes are
evaluated based on daily and peak hour totals. The “Second Criteria” includes
several traffic measures as follows:
85th Percentile Speed: This is the speed at which 85 percent of the motorist
are traveling.
Correctable Accidents: This would include only accidents that would be
correctable by the installation of Traffic Calming devices.
Cut Through Traffic: This is traffic that is looking to minimize their travel time by
avoiding congested arterial streets and cutting through neighborhood
streets.
Pedestrian Crossing Volume: This is the volume of pedestrian crossing streets
that are affected and in conflict with the traffic traveling along those streets.
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Table 5: Miami-Dade County Policy for Traffic Calming Measures
Traffic Calming Evaluation & Appraisal
The traffic data documented in this report was analyzed to determine whether it
meets the Miami-Dade County Policy for Traffic Calming Measures.
Minimum Traffic Volume
This criterion is met when the traffic volumes exceed 1,500 vehicles per day (vpd) or
150 vehicles during the peak hours (vph). The studied corridor is a local street and
therefore, the existing traffic volumes were compared to the first criterion, Minimum
Traffic Volume for Residential Local Streets. As a result, the traffic data exceeded
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No. Name AM Peak PM Peak AM Peak PM Peak
YES
Roadway Link
YES
YES
Peak Hour Volume > 150 VPH
225
97 2491,700 MET
2
113
NOT MET
NOT MET
3
At
1 SW 78 Street east of US 1
(US1 - South Miami Elks Drive)
93
Criterion
Satisfied
SW 78 Street
west of SW 63 Avenue
(South Miami Elks Drive -
SW 63 Avenue)
MET
MET
2,100
MET
SW 78 Street west of SW 62 Avenue
(SW 63 Avenue - SW 62 Avenue)
1,800
Primary Criterion: Minimum Traffic Volume
NOT MET183MET
Two-Way
Peak Hour VolumeADT
(Rounded)ADT > 1,500 VPD
MET
the Minimum Traffic Volume threshold for Residential Local Streets and therefore,
the first criterion is met. Table 6 summarizes the results for each location.
Table 6: Minimum Traffic Volume Criterion
85th Percentile Speed
This criterion was evaluated to determine if the existing vehicular speed is a
concern at the studied locations. A speeding issue can be identified when the 85th
percentile speed of all vehicles is at least 10 miles per hour (MPH) greater than the
posted speed. The posted speed within the study area is 25 MPH and therefore, the
85th percentile speed data must reveal 35 MPH or greater to meet this criterion.
Based on the existing speed data, the highest 85th percentile speed within the
study area is 28 MPH and does not meet the speed criterion. Table 7 below
summarizes the average speed and the 85th percentile speed for the study area.
Correctable Accidents, Cut Through Traffic & Pedestrian Crossing Volume
Although no data was gathered to quantify accidents, cut through traffic and
pedestrian volume, our field observations revealed there are no issues regarding
the referenced criteria. However, in addition to the above, the following
observations were made during the field review:
No evidence of crashes or accidents
No cut through traffic was identified
Pedestrian volume was low to nonexistent
Therefore, this study assumes that the study area does not meet the criterion of
Correctable Accidents, Cut Through Traffic and Pedestrian Crossing Volume.
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No. Name
EB 21 NOT MET
WB 23 NOT MET
EB 21 NOT MET
WB 23 NOT MET
EB 28 NOT MET
WB 27 NOT MET
SW 78 Street
west of SW 63 Avenue
(South Miami Elks Drive -
SW 63 Avenue)
SW 78 Street west of SW 62 Avenue
(SW 63 Avenue - SW 62 Avenue)
At
1 SW 78 Street east of US 1
(US1 - South Miami Elks Drive)
3
2 NO
Criterion
SatisfiedDirection
NO
Roadway Link
85th Percentile
Speed (MPH)
85th Percentile
Speed:
10 MPH > Posted
Speed Limit
Other Criterion: 85th Percentile Speed
NO
Table 7: 85th Percentile Speed Criterion
Municipal Boundary Considerations
In addition to the criteria outlined above, the Miami-Dade County’s Traffic Flow
Modification(s) /Street Closure(s) Procedure allows for certain reductions in the
threshold shown in Table 5. These are shown as footnote *** as follows:
*** The traffic volume within a municipal boundary could be
reduced by a total of 30% and speed by 50% at the request of
and for those municipalities, which provide funding for their
traffic calming program.
The application of this criterion would still not meet the speed threshold of 30 MPH
(25 MPH posted plus 5 MPH or 50% of 10 MPH). However, since the volume criteria is
still met under this analysis as well, the City of South Miami could obtain
“Concurrence from affected residential/Property owners,” with a 2/3 of returned
ballots. Lastly, the code states:
Municipal Jurisdictions: In Lieu of concurrence a resolution is
acceptable from municipalities.
In summary, although traffic volumes exist to support traffic calming within the
subject study area, the lack of a secondary criteria will require the City to obtain a
two-thirds (2/3) concurrence from affected residents or pass a resolution. If either is
secured by the City, we would recommend the following traffic calming options:
Traffic Circle at SW 78th Street & SW 63 Avenue/SM Elks Drive
Traffic Circle at SW 78th Street & SW 63 Avenue
Midblock Traffic Calming on SW 78th Street between SW 62nd & 63rd Avenue
o Choker or Neckdown/Narrowing traffic lanes
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Conclusion
In conclusion, the traffic calming analysis documented in this report reveals that SW
78th Street (between US 1 - SW 62nd Avenue) does not meet the MDCPWD traffic
calming criteria. The existing traffic data did satisfy the first criteria (Minimum Traffic
Volume), no other criterion was met and would require City action to implement.
Therefore, since traffic volumes do exist to support traffic calming within the subject
study area, the lack of a secondary criteria will require the City to obtain a two-
thirds (2/3) concurrence from affected residents or pass a resolution. If either is
secured by the City, we would recommend the following traffic calming options:
Traffic Circle at SW 78th Street & SW 63 Avenue/SM Elks Drive
Traffic Circle at SW 78th Street & SW 63 Avenue
Midblock Traffic Calming on SW 78th Street between SW 62nd & 63rd Avenue
Choker or Neckdown/Narrowing traffic lanes
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